文档库 最新最全的文档下载
当前位置:文档库 › Emergence of communication in teams of embodied and situated agents, in The Evolution of La

Emergence of communication in teams of embodied and situated agents, in The Evolution of La

Emergence of communication in teams of embodied and situated agents, in The Evolution of La
Emergence of communication in teams of embodied and situated agents, in The Evolution of La

EMERGENCE OF COMMUNICATION IN TEAMS OF

EMBODIED AND SITUATED AGENTS

DAVIDE MAROCCO S TEFANO NOLFI

Institute of Cognitive Science and Technologies, CNR, Via San Martino della

Battaglia 44, Rome, 00185, Italy

In this paper we will describe the results of an experiment in which an effective

communication system arises among a collection of initially non-communicating agents

through a self-organization process based on an evolutionary process. Evolved agents

communicate by producing and detecting five different signals that affect both their

motor and signaling behavior. These signals identify features of the environment and of

the agents/agents and agents/environmental relations that are crucial for solving the given

problem. The obtained results also indicate that individual and social/communicative

behaviors are tightly co-adapted.

1.Introduction

The development of embodied agents able to interact autonomously with the physical world and to communicate on the basis of a self-organizing communication system is a new exciting field of research (Steels and Vogt, 1997; Cangelosi and Parisi, 1998; Steels, 1999; Marocco, Cangelosi and Nolfi, 2003; Quinn et al, 2003; for a review see Kirby, 2002; Steels, 2003; Wagner et al., 2003; Nolfi, in press). The objective is to identify methods of how a population of agents equipped with a sensory-motor system and a cognitive apparatus can develop a grounded communication system and use their communication abilities to solve a given problem. Such communication systems may have similar characteristics to animal communication or human language.

In this paper we will describe the results of an experiment in which an effective communication system arises among a collection of initially non-communicating agents through a self-organization process based on artificial evolution. Unlike other experimental setup in which the interaction between agents or the motor behavior of agents is pre-determined and fixed (e.g. Steels, 1999; Marocco, Cangelosi, and Nolfi, 2003) evolving agents have to autonomously determine: (a) their individual behavior (i.e. how they behave on the basis of their sensory information when signals produced by other agents cannot be detected), (b) their communicative behavior (i.e. when and how many signals are produced, the context in which signals are produced, the type and number of signals produced, the effect of signals detected on the individual motor and signaling behavior, the modalities with which agents communicate).

2.Experimental set-up

A team of four simulated robots that “live” in the same environment (i.e. a white arena of 270x270cm surrounded by white walls containing two grey target areas, Figure 1, left) are evolved for the ability to solve a collective navigation problem. Robots are provided with simple sensory-motor capabilities that allow them to move, produce signals with varying intensities, and to gather information from their physical and social environment (including signals produced by other agents). The control system of the robots is an artificial neural network.

The robots have a circular body with a radius of 11 cm and the robots’ neural controllers consist of neural networks with 14 sensory neurons (that encode the activation states of the 8 infrared sensors that allow the robots to detect obstacles, 1 ground sensor that allow robots to detect the color of the floor, 4 communicative sensors that allow robots to detect the signals emitted by nearby robots, and 1 sensor that encode the activation state of the communication actuator at times t-1, i.e. each robot can hear its own emitted signal at the previous time step) directly connected to the three motor neurons that control the desired speed of the two wheels and the intensity of the communication signal produced by the robot. The neural controllers also include two hidden neurons that receive connection from the sensory neurons and from themselves and send connections to the motor and communicating neurons (Figure 1, right). The communication sensors can detect signals produced by other robots up to a distance of 100cm from four corresponding directions (i.e. frontal [315o-45o], rear [135o-225o], left [225o-315o], right [45o-135o]).

Figure 1. Left: The environment and the robots. The square represents the arena surrounded by walls. The two grey circles represent two target areas. The four black circles represent four robots. Right: The neural controller evolving robots. Internal neurons and recurrent connections are only included in one of the two experimental setting (see text).

Agents were evolved (Nolfi and Floreano, 2000) for the ability to find and remain in the target areas by subdividing themselves equally between the two areas. In particular, the fitness of the team of robots consists of the sum of 0.25 scores for each robot located in a target area and a score of -1.00 for each extra robot (i.e. each robot exceeding the maximum number of two) located in a target area. The total fitness of a team is computed by summing the fitness gathered by the four robots in each time step. The initial population consisted of 100 randomly generated genotypes that encoded the connection weights of 100 corresponding neural controllers. Each genotype is translated into 4 identical neural controllers that are embodied in the four corresponding robots. The evolutionary process lasted 100 generations. Each generation the 20 best genotypes were allowed to reproduce by generating five copies each, with 2% of their bits replaced with a new randomly selected value.

3.The evolved behaviour

By analyzing the behavior of one of the best team of evolved robots we can see that evolved robots are able to find and remain in the two target areas by equally dividing between the two. In the example shown in left side of the Figure 2, robots 2 and 3 quickly reach two different empty target areas. Later on, robot 1 and then robot 0 approach and enter in the bottom-right target area. As soon as the third robot (i.e. robot 0) enter in the area, robot 1 leaves the bottom-right target area and, after exploring the environment for a while, enters and remains in the top-left target area.

Figure 2. Left: The behavior displayed by the team of evolved robots of one of the best replications. The square and the gray circles indicate the arena and the target area respectively. Lines inside the arena indicate the trajectory of the four robots during a trial. The numbers indicate the starting and ending position of the corresponding robot (the ending position is marked with a white circle). Right: Average fitness of all teams of the last generations of 10 different replications of the experiment in a Normal, Deprived, and No-signals condition. In all cases, individuals have been tested for 1000 trials.

To determine whether the possibility to signal and to use other robots’ signals is exploited by evolving robots we tested the evolved team in three conditions: a “Normal” condition, a “Deprived” condition in which robots evolved in a normal condition were tested in a control condition in which the state of communication sensors was always set to a null value, and a “No-signal” conditions in which robots were evolved and tested with their communication sensors always set to a null value (see Figure 2, right). The fact that performance in the “Normal” condition are better and statistically different (p<0.001) from the other two control conditions indicates that communication plays a role. Performance in the “Deprived” and “No-signals” conditions are not statistically different.

4.The communication system of evolved agents

By analyzing the communication system we observed that evolved agents produce different signals (as we said above, signals consists of single values ranging between [0,1]) and react to detected signals by modifying both their motor and signaling behavior.

For example, in one of the best replication of the experiment, evolved agents produce and use five different signals: a signal A with an intensity of about 0.42 produced by robots located outside the target areas not interacting with other robots located inside target areas; a signal B with an intensity of about 0.85 produced by robots located alone inside a target area; a signal C, an oscillatory signal with an average intensity of 0.57, produced by robots located inside a target area that also contains another robot (i.e. when robots detect a signal produced by a robot also located in a target area); a signal D with an almost null intensity produced by robots outside target areas that are approaching a target area and are interacting with another robot located inside the target area; and a signal E, an oscillatory signal with an average intensity of 0.33, emitted by robots located outside the target areas interacting with other robots also located outside target areas.

Detected signals affect the robots’ motor and signaling behavior as follows: (1) robots located outside the target areas receiving signal E modify their motor trajectory so to reduce the time needed to reach a target area, on the average; (2) robots located outside target areas receiving signal B modify their motor behavior by approaching the robot emitting the signal (i.e. by approaching the target area in which the robot emitting the signal is located) and their signaling behavior (i.e. by producing signal D instead of signal A); (3) robots located outside the target areas detecting the signal C modify their motor behavior so as

to tend to move away from the signal source; (4) r obots located inside the target areas detecting the signal C modify their motor behavior so to increase their likeness to exit from the target area, (5) r obots located outside the target areas detecting the signal A modify their signaling behavior by producing signal E instead of signal A. The functionality of signals have been identified and demonstrated through experimental tests that we do not report in this paper for space reasons.

5.Relation between individual and social/communicative behavior

Since robots individual and social/communicative behavior are allowed to co-evolve we might wonder what the relation between these two forms of behaviors is and how the possibility to co-adapt them is exploited by evolved individuals.

The fact that agents tested in a condition in which signals produced by other agents cannot be detected (Figure 2, right, “Deprived” condition) perform similar to agents evolved and tested in this condition (Figure 2, right, “No-Signal” condition) indicates that evolved agents tend to optimize both their individual and social/communicative behavior. The adaptive pressure toward the development of an effective individual behavior can be explained by considering that signals produced by other agents are not always available since the signals that are produced and detected depends on the current position of the other agents that is partially unpredictable since agents start from randomly initialized positions and orientations.

Indeed, the analysis of the individual behavior (i.e. the behavior of agents that are not allowed to detect other agents signals) exhibited by evolved agents indicates that they are able to solve the navigation problem to a good extent. Indeed, by avoiding walls, by exhibiting curvilinear trajectories when far from walls, and by remaining in the target areas as soon as they enter into one of them, evolved agents are able to find and remain in the two target areas most of the times even in a “Deprived” condition. Figure 3 shows how evolved agents tested in a “Deprived” condition spend about 60% of their lifetime in the conditions in which the team gathers a positive fitness.

Communication is used by evolved agents as an additional mechanism, with respect to their individual capabilities, that allow them to correct mistakes produced by their individual behaviors (e.g. to exit from target area that contains more than two agents) and to improve some of their abilities that are accomplished through their individual behavior (e.g. by reducing the time required to reach target areas, on the average or the ability to directly move

toward a target area that contains a single agent by exploiting the signal produced by the agent already located in the target area). These improvements are reflected in the data shown in Figure 3 that, for example, indicates that agents spend much less time in target areas that already contains two or three other robots in a “Normal” rather than in a “Deprived” condition.

Figure 3. Percentage of lifecycles spent by a team of four agents (of the best evolved team) in the 8 possible different states tested in a “Normal” condition (gray bars) and in a “Deprived” condition in which agents are not allowed to detect other agents’ signals. “Void” indicate the case in which all the four agents are located outside target areas (fitness = 0.0). “1” indicates the case in which only a single agent is located in a target area (fitness = 0.25). “2” indicates the case in which two agents are located in target areas (fitness = 0.5). “1+2” indicates the case in which one agent is located in a target area and two other agents are located in the other target area (fitness = 0.75). “2+2” indicates the case in which each of the two target area contains two agents (fitness = 1.0). “1+3” the case in which one target area contains one agent and the other three agents (fitness = 0.0). “3” indicates the case in which three agents are located in the same target area (fitness = -0.25). “4” indicates the case in which four agents are located in the same target area (fitness = -1.0). Average performance obtained by testing the agents for 1000 trials lasting 1000 cycles.

6.Discussion

In this paper we described the results of an experiment in which an effective communication system arises among a collection of initially non-communicating agents evolved for the ability to solve a collective navigation problem. With the methodology chosen, we observed that agents developed autonomously (i.e. without human intervention), first of all, an effective individual behavior that allow agents to cope the navigation problems without the collaboration of the other agents allowed by communication.

In addition, agents developed a n effective communication system based on five different signals that correspond to crucial features of the environment, of the agents/agents relations, and agents/environmental relations (e.g. the relative location of a target area, the number of agents contained in a target area, etc.). These features, that have been autonomously discovered by the agents and that are grounded in agents’ sensory-motor experiences, constitute the ‘meanings’ of the signals produced and detected by the agents. Used signals, therefore, do not only refer to the characteristics of the physical environment but also to those of the social environment constituted by the other agents and by their current state.

The analysis of the obtained results also indicate that individual and social/communicative behaviors are tightly co-adapted. In fact, since individual behavior in evolved agents are optimized as well as social/communicative behavior, detected signals act as a sort of additional mechanism that enhances individual behavior (when signals are available). On the other hand, individual behavior, in absence of useful signals, guarantees the maximum performance that can be achieved on the basis of the available sensory information.

The individual behavior also creates the basis for the exploitation of signaling capabilities. For example, the individual ability to reach and remain in a target area represents a pre-condition for the emergence of an ability to signal the relative position of a target area and to use that signal appropriately. Similarly the limits of the individual behavior, for instance the tendency to enter into a target area that already contains two other agents, represents a pre-condition for the development of communication abilities that allow agents to exit from target areas that contains more than two agents.

Interestingly, one can find interesting similarities between the communication systems observed in our experiments and forms of animal communication described in the literature. For instance, signals that refer to agent/environment interactions are similar to alarm calls or food calls in birds and primates that provide information about objects or events that are external to the animal that emits the signal (Hauser, 1996). Moreover, the coordinated oscillatory signals produced by two robots located in the same target area (that allow the robots to keep additional robots away while maintaining the couple of robots in the area) are similar to the synchronized communicative interactions known as vocal duetting produced by several animals. Indeed, as in the case of the robots described in this paper, in some birds duets play an important cooperative function since they allow the members of a couple of animals to defend their territory and/or to keep the pair bond (Langmore, 1998; Slater, 1997).

Acknowledgments

The research has been supported by the ECAGENTS project founded by the Future and Emerging Technologies programme (IST-FET) of the European Community under EU R&D contract IST-2003-1940.

References

Cangelosi, A., & Parisi, D. (1998) The emergence of a ‘language’ in an evolving population of neural networks. Connection Science, 10: 83-97. Hauser, M. D. (1996) The evolution of communication, Cambridge MA: MIT Press.

Kirby, S. (2002). Natural Language from Artificial Life. Artificial Life, 8(2):185--215.

Langmore, N. E. (1998) Functions of duets and solo songs of female birds, Trends in Ecology and Evolution,13: 136-140.

Marocco, D., Cangelosi, A., & Nolfi, S. (2003), The emergence of communication in evolutionary robots. Philosophical Transactions of the Royal Society London - A, 361: 2397-2421.

Nolfi, S. (in press). Emergence of Communication in Embodied Agents: Co-Adapting Communicative and Non-Communicative Behaviours.

Connection Science.

Nolfi, S., & Floreano, D. (2000). Evolutionary Robotics: The Biology, Intelligence, and Technology of Self-Organizing Machines. Cambridge, MA: MIT Press/Bradford Books.

Quinn, M., Smith, L., Mayley, G., & Husbands, P. (2003) Evolving controllers for a homogeneous system of physical robots: Structured cooperation with minimal sensors. Philosophical Transactions of the Royal Society of London, Series A: Mathematical, Physical and Engineering Sciences

361:2321-2344.

Slater, P. J. B. (1997) Singing in the rain forest: the duets of bay wrens, Trends in Ecology and Evolution, 12: 207-208.

Steels, L. (1999). The Talking Heads Experiment, Antwerpen, Laboratorium.

Limited Pre-edition.

Steels, L. (2003) Evolving grounded communication for robots. Trends in Cognitive Science. 7(7): 308-312.

Steels, L., & Vogt, P. (1997) Grounding adaptive language games in robotic agents. In: P. Husband & I. Harvey (Eds.), Proceedings of the 4th European Conference on Artificial Life, p. 474-482. Cambridge MA: MIT Press.

Wagner, K., Reggia, J.A., Uriagereka J., & Wilkinson, G.S. (2003). Progress in the simulation of emergent communication and language. Adaptive Behavior, 11(1):37-69.

英语中的比较级与最高级 详解

比较级与最高级 1.as...as 与(not) as(so)...as as...as...句型中,as的词性 第一个as是副词,用在形容词和副词的原级前,常译为“同样地”。第二个as是连词,连接与前面句子结构相同的一个句子(相同部分常省略),可译为“同..... He is as tall as his brother is (tall) . (后面的as 为连词) 只有在否定句中,第一个as才可换为so 改错: He is so tall as his brother.(X) 2.在比较状语从句中,主句和从句的句式结构一般是相同的 与as...as 句式中第二个as一样,than 也是连词。as和than这两个连词后面的从句的结构与前面的句子大部分情况下结构是相同的,相同部分可以省略。 He picked more apples than she did. 完整的表达为: He picked more apples than she picked apples. 后而的picked apples和前面相同,用did 替代。 He walked as slowly as she did.完整表达为: He walked as slowly as she walked slowly. she后面walked slowly与前面相同,用did替代。

3.谓语的替代 在as和than 引导的比较状语从句中,由于句式同前面 主句相同,为避免重复,常把主句中出现而从句中又出现的动词用do的适当形式来代替。 John speaks German as fluently as Mary does. 4.前后的比较对象应一致 不管后面连词是than 还是as,前后的比较对象应一致。The weather of Beijing is colder than Guangzhou. x than前面比较对象是“天气”,than 后面比较对象是“广州”,不能相比较。应改为: The weather of Bejing is colder than that of Guangzhou. 再如: His handwriting is as good as me. 应改为: His handwriting is as good as mine. 5.可以修饰比较级的词 常用来修饰比较级的词或短语有: Much,even,far,a little,a lot,a bit,by far,rather,any,still,a great deal等。 by far的用法: 用于强调,意为“...得多”“最最...”“显然”等,可修饰形容词或副词的比较级和最高级,通常置于其后,但是若比较级或最高级前有冠词,则可置于其前或其后。

The way常见用法

The way 的用法 Ⅰ常见用法: 1)the way+ that 2)the way + in which(最为正式的用法) 3)the way + 省略(最为自然的用法) 举例:I like the way in which he talks. I like the way that he talks. I like the way he talks. Ⅱ习惯用法: 在当代美国英语中,the way用作为副词的对格,“the way+ 从句”实际上相当于一个状语从句来修饰整个句子。 1)The way =as I am talking to you just the way I’d talk to my own child. He did not do it the way his friends did. Most fruits are naturally sweet and we can eat them just the way they are—all we have to do is to clean and peel them. 2)The way= according to the way/ judging from the way The way you answer the question, you are an excellent student. The way most people look at you, you’d think trash man is a monster. 3)The way =how/ how much No one can imagine the way he missed her. 4)The way =because

人教版(新目标)初中英语形容词与副词的比较级与最高级

人教版(新目标)初中英语形容词与副词的比较级与最高级 (一)规则变化: 1.绝大多数的单音节和少数双音节词,加词尾-er ,-est tall—taller—tallest 2.以不发音的e结尾的单音节词和少数以-le结尾的双音节词只加-r,-st nice—nicer—nicest , able—abler—ablest 3.以一个辅音字母结尾的重读闭音节词或少数双音节词,双写结尾的辅音字母,再加-er,-est big—bigger—biggest 4.以辅音字母加y结尾的双音节词,改y为i再加-er,-est easy—easier—easiest 5.少数以-er,-ow结尾的双音节词末尾加-er,-est clever—cleverer—cleverest, narrow—narrower—narrowest 6.其他双音节词和多音节词,在前面加more,most来构成比较级和最高级 easily—more easily—most easily (二)不规则变化 常见的有: good / well—better—best ; bad (ly)/ ill—worse—worst ; old—older/elder—oldest/eldest many / much—more—most ; little—less—least ; far—farther/further—farthest/furthest

用法: 1.原级比较:as + adj./adv. +as(否定为not so/as + adj./adv. +as)当as… as中间有名字时,采用as + adj. + a + n.或as + many / much + n. This is as good an example as the other is . I can carry as much paper as you can. 表示倍数的词或其他程度副词做修饰语时放在as的前面 This room is twice as big as that one. 倍数+as+adj.+as = 倍数+the +n.+of Your room is twice as larger as mine. = Your room is twice the size of mine. 2.比较级+ than 比较级前可加程度状语much, still, even, far, a lot, a little, three years. five times,20%等 He is three years older than I (am). 表示“(两个中)较……的那个”时,比较级前常加the(后面有名字时前面才能加冠词) He is the taller of the two brothers. / He is taller than his two brothers. Which is larger, Canada or Australia? / Which is the larger country, Canada or Australia? 可用比较级形式表示最高级概念,关键是要用或或否定词等把一事物(或人)与其他同类事物(或人)相分离 He is taller than any other boy / anybody else.

英语中的比较级和最高级

大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基础上变化的。分为规则变化和不规则变化。 规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加 -er 和 -est 构成。 great (原级) (比较级) (最高级) 2) 以 -e 结尾的单音节形容词的比较级和最高级是在词尾加 -r 和 -st 构成。wide (原级) (比较级) (最高级) 3)少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和 -est 构成。 clever(原级) (比较级) (最高级) 4) 以 -y 结尾,但 -y 前是辅音字母的形容词的比较级和最高级是把 -y 去掉,加上 -ier 和-est 构成. happy (原形) (比较级) (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该辅音字母然后再加 -er和-est。 big (原级) (比较级) (最高级) 6) 双音节和多音节形容词的比较级和最高级需用more 和 most 加在形容词前面来构成。 beautiful (原级) (比较级) (比较级) difficult (原级) (最高级) (最高级) 常用的不规则变化的形容词的比较级和最高级: 原级------比较级------最高级 good------better------best many------more------most much------more------most bad------worse------worst far------farther, further------farthest, furthest 形容词前如加 less 和 least 则表示"较不"和"最不 形容词比较级的用法: 形容词的比较级用于两个人或事物的比较,其结构形式如下: 主语+谓语(系动词)+ 形容词比较级+than+ 对比成分。也就是, 含有形容词比较级的主句+than+从句。注意从句常常省去意义上和主句相同的部分, 而只剩下对比的成分。

The way的用法及其含义(二)

The way的用法及其含义(二) 二、the way在句中的语法作用 the way在句中可以作主语、宾语或表语: 1.作主语 The way you are doing it is completely crazy.你这个干法简直发疯。 The way she puts on that accent really irritates me. 她故意操那种口音的样子实在令我恼火。The way she behaved towards him was utterly ruthless. 她对待他真是无情至极。 Words are important, but the way a person stands, folds his or her arms or moves his or her hands can also give us information about his or her feelings. 言语固然重要,但人的站姿,抱臂的方式和手势也回告诉我们他(她)的情感。 2.作宾语 I hate the way she stared at me.我讨厌她盯我看的样子。 We like the way that her hair hangs down.我们喜欢她的头发笔直地垂下来。 You could tell she was foreign by the way she was dressed. 从她的穿著就可以看出她是外国人。 She could not hide her amusement at the way he was dancing. 她见他跳舞的姿势,忍俊不禁。 3.作表语 This is the way the accident happened.这就是事故如何发生的。 Believe it or not, that's the way it is. 信不信由你, 反正事情就是这样。 That's the way I look at it, too. 我也是这么想。 That was the way minority nationalities were treated in old China. 那就是少数民族在旧中

英语比较级和最高级的用法归纳

英语比较级和最高级的用法归纳 在学习英语过程中,会遇到很多的语法问题,比如比较级和最高级的用法,对于 这些语法你能够掌握吗?下面是小编整理的英语比较级和最高级的用法,欢迎阅读! 英语比较级和最高级的用法 一、形容词、副词的比较级和最高级的构成规则 1.一般单音节词和少数以-er,-ow结尾的双音节词,比较级在后面加-er,最高级 在后面加-est; (1)单音节词 如:small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest (2)双音节词 如:clever→cleverer→cleverest narrow→narrower→narrowest 2.以不发音e结尾的单音节词,比较在原级后加-r,最高级在原级后加-st; 如:large→larger→largest nice→nicer→nicest able→abler→ablest 3.在重读闭音节(即:辅音+元音+辅音)中,先双写末尾的辅音字母,比较级加-er,最高级加-est; 如:big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4.以“辅音字母+y”结尾的双音节词,把y改为i,比较级加-er,最高级加-est; 如:easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5.其他双音节词和多音节词,比较级在前面加more,最高级在前面加most; 如:bea utiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily 注意:(1)形容词最高级前通常必须用定冠词 the,副词最高级前可不用。 例句: The Sahara is the biggest desert in the world. (2) 形容词most前面没有the,不表示最高级的含义,只表示"非常"。 It is a most important problem. =It is a very important problem.

(完整版)the的用法

定冠词the的用法: 定冠词the与指示代词this ,that同源,有“那(这)个”的意思,但较弱,可以和一个名词连用,来表示某个或某些特定的人或东西. (1)特指双方都明白的人或物 Take the medicine.把药吃了. (2)上文提到过的人或事 He bought a house.他买了幢房子. I've been to the house.我去过那幢房子. (3)指世界上独一无二的事物 the sun ,the sky ,the moon, the earth (4)单数名词连用表示一类事物 the dollar 美元 the fox 狐狸 或与形容词或分词连用,表示一类人 the rich 富人 the living 生者 (5)用在序数词和形容词最高级,及形容词等前面 Where do you live?你住在哪? I live on the second floor.我住在二楼. That's the very thing I've been looking for.那正是我要找的东西. (6)与复数名词连用,指整个群体 They are the teachers of this school.(指全体教师) They are teachers of this school.(指部分教师) (7)表示所有,相当于物主代词,用在表示身体部位的名词前 She caught me by the arm.她抓住了我的手臂. (8)用在某些有普通名词构成的国家名称,机关团体,阶级等专有名词前 the People's Republic of China 中华人民共和国 the United States 美国 (9)用在表示乐器的名词前 She plays the piano.她会弹钢琴. (10)用在姓氏的复数名词之前,表示一家人 the Greens 格林一家人(或格林夫妇) (11)用在惯用语中 in the day, in the morning... the day before yesterday, the next morning... in the sky... in the dark... in the end... on the whole, by the way...

英语比较级和最高级的用法

More than的用法 A. “More than+名词”表示“不仅仅是” 1)Modern science is more than a large amount of information. 2)Jason is more than a lecturer; he is a writer, too. 3) We need more than material wealth to build our country.建设我们国家,不仅仅需要物质财富. B. “More than+数词”含“以上”或“不止”之意,如: 4)I have known David for more than 20 years. 5)Let's carry out the test with more than the sample copy. 6) More than one person has made this suggestion. 不止一人提过这个建议. C. “More than+形容词”等于“很”或“非常”的意思,如: 7)In doing scientific experiments, one must be more than careful with the instruments. 8)I assure you I am more than glad to help you. D. more than + (that)从句,其基本意义是“超过(=over)”,但可译成“简直不”“远非”.难以,完全不能(其后通常连用情态动词can) 9) That is more than I can understand . 那非我所能懂的. 10) That is more than I can tell. 那事我实在不明白。 11) The heat there was more than he could stand. 那儿的炎热程度是他所不能忍受的 此外,“more than”也在一些惯用语中出现,如: more...than 的用法 1. 比……多,比……更 He has more books than me. 他的书比我多。 He is more careful than the others. 他比其他人更仔细。 2. 与其……不如 He is more lucky than clever. 与其说他聪明,不如说他幸运。 He is more (a)scholar than (a)teacher. 与其说他是位教师,不如说他是位学者。 注:该句型主要用于同一个人或物在两个不同性质或特征等方面的比较,其中的比较级必须用加more 的形式,不能用加词尾-er 的形式。 No more than/not more than 1. no more than 的意思是“仅仅”“只有”“最多不超过”,强调少。如: --This test takes no more than thirty minutes. 这个测验只要30分钟。 --The pub was no more than half full. 该酒吧的上座率最多不超过五成。-For thirty years,he had done no more than he (had)needed to. 30年来,他只干了他需要干的工作。 2. not more than 为more than (多于)的否定式,其意为“不多于”“不超过”。如:Not more than 10 guests came to her birthday party. 来参加她的生日宴会的客人不超过十人。 比较: She has no more than three hats. 她只有3顶帽子。(太少了) She has not more than three hats. 她至多有3顶帽子。(也许不到3顶帽子) I have no more than five yuan in my pocket. 我口袋里的钱最多不过5元。(言其少) I have not more than five yuan in my pocket. 我口袋里的钱不多于5元。(也许不到5元) more than, less than 的用法 1. (指数量)不到,不足 It’s less than half an hour’s drive from here. 开车到那里不到半个钟头。 In less than an hour he finished the work. 没要上一个小时,他就完成了工作。 2. 比……(小)少 She eats less than she should. 她吃得比她应该吃的少。 Half the group felt they spent less than average. 半数人觉得他们的花费低于平均水平。 more…than,/no more than/not more than (1)Mr.Li is ________ a professor; he is also a famous scientist. (2)As I had ________ five dollars with me, I couldn’t afford the new jacket then. (3)He had to work at the age of ________ twelve. (4)There were ________ ten chairs in the room.However, the number of the children is twelve. (5)If you tel l your father what you’ve done, he’ll be ________ angry. (6)-What did you think of this novel? -I was disappointed to find it ________ interesting ________ that one. 倍数表达法 1. “倍数+形容词(或副词)的比较级+than+从句”表示“A比B大(长、高、宽等)多少倍” This rope is twice longer than that one.这根绳是那根绳的三倍(比那根绳长两倍)。The car runs twice faster than that truck.这辆小车的速度比那辆卡车快两倍(是那辆卡车的三倍)。 2. “倍数+as+形容词或副词的原级+as+从句”表示“A正好是B的多少倍”。

“the way+从句”结构的意义及用法

“theway+从句”结构的意义及用法 首先让我们来看下面这个句子: Read the followingpassageand talkabout it wi th your classmates.Try totell whatyou think of Tom and ofthe way the childrentreated him. 在这个句子中,the way是先行词,后面是省略了关系副词that或in which的定语从句。 下面我们将叙述“the way+从句”结构的用法。 1.the way之后,引导定语从句的关系词是that而不是how,因此,<<现代英语惯用法词典>>中所给出的下面两个句子是错误的:This is thewayhowithappened. This is the way how he always treats me. 2.在正式语体中,that可被in which所代替;在非正式语体中,that则往往省略。由此我们得到theway后接定语从句时的三种模式:1) the way+that-从句2)the way +in which-从句3) the way +从句 例如:The way(in which ,that) thesecomrade slookatproblems is wrong.这些同志看问题的方法

不对。 Theway(that ,in which)you’re doingit is comple tely crazy.你这么个干法,简直发疯。 Weadmired him for theway inwhich he facesdifficulties. Wallace and Darwingreed on the way inwhi ch different forms of life had begun.华莱士和达尔文对不同类型的生物是如何起源的持相同的观点。 This is the way(that) hedid it. I likedthe way(that) sheorganized the meeting. 3.theway(that)有时可以与how(作“如何”解)通用。例如: That’s the way(that) shespoke. = That’s how shespoke.

初中英语比较级和最高级讲解与练习

初中英语比较级和最高级讲解与练习 形容词比较级和最高级 一.绝大多数形容词有三种形式,原级,比较级和最高级, 以表示形容词说明的性质在程度上的不同。 1. 形容词的原级: 形容词的原级形式就是词典中出现的形容词的原形。例如: poor tall great glad bad 2. 形容词的比较级和最高级: 形容词的比较级和最高级形式是在形容词的原级形式的基 础上变化的。分为规则变化和不规则变化。 二.形容词比较级和最高级规则变化如下: 1) 单音节形容词的比较级和最高级形式是在词尾加-er 和-est 构成。 great (原级) greater(比较级) greatest(最高级) 2) 以-e 结尾的单音节形容词的比较级和最高级是在词尾加-r 和-st 构成。 wide (原级) wider (比较级) widest (最高级) 3) 少数以-y, -er, -ow, -ble结尾的双音节形容词的比较级和最高级是在词尾加 -er 和-est构成。 clever(原级) cleverer(比较级) cleverest(最高级), slow(原级) slower(比较级) slowest (最高级) 4) 以-y 结尾,但-y 前是辅音字母的形容词的比较级和最高级是把-y 去掉,加上-ier 和-est 构成. happy (原形) happier (比较级) happiest (最高级) 5) 以一个辅音字母结尾其前面的元音字母发短元音的形容词的比较级和最高级是双写该 辅音字母然后再加-er和-est。 原形比较级最高级原形比较级最高级 big bigger biggest hot hotter hottest red redder reddest thin thinner thinnest 6) 双音节和多音节形容词的比较级和最高级需用more 和most 加在形容词前面来构 成。 原形比较级最高级 careful careful more careful most careful difficult more difficult most difficult delicious more delicious most delicious 7)常用的不规则变化的形容词的比较级和最高级: 原级比较级最高级 good better best 好的 well better best 身体好的 bad worse worst 坏的 ill worse worst 病的 many more most 许多 much more most 许多 few less least 少数几个 little less least 少数一点儿 (little littler littlest 小的) far further furthest 远(指更进一步,深度。亦可指更远) far farther farthest 远(指更远,路程)

way 用法

表示“方式”、“方法”,注意以下用法: 1.表示用某种方法或按某种方式,通常用介词in(此介词有时可省略)。如: Do it (in) your own way. 按你自己的方法做吧。 Please do not talk (in) that way. 请不要那样说。 2.表示做某事的方式或方法,其后可接不定式或of doing sth。 如: It’s the best way of studying [to study] English. 这是学习英语的最好方法。 There are different ways to do [of doing] it. 做这事有不同的办法。 3.其后通常可直接跟一个定语从句(不用任何引导词),也可跟由that 或in which 引导的定语从句,但是其后的从句不能由how 来引导。如: 我不喜欢他说话的态度。 正:I don’t like the way he spoke. 正:I don’t like the way that he spoke. 正:I don’t like the way in which he spoke. 误:I don’t like the way how he spoke. 4.注意以下各句the way 的用法: That’s the way (=how) he spoke. 那就是他说话的方式。 Nobody else loves you the way(=as) I do. 没有人像我这样爱你。 The way (=According as) you are studying now, you won’tmake much progress. 根据你现在学习情况来看,你不会有多大的进步。 2007年陕西省高考英语中有这样一道单项填空题: ——I think he is taking an active part insocial work. ——I agree with you_____. A、in a way B、on the way C、by the way D、in the way 此题答案选A。要想弄清为什么选A,而不选其他几项,则要弄清选项中含way的四个短语的不同意义和用法,下面我们就对此作一归纳和小结。 一、in a way的用法 表示:在一定程度上,从某方面说。如: In a way he was right.在某种程度上他是对的。注:in a way也可说成in one way。 二、on the way的用法 1、表示:即将来(去),就要来(去)。如: Spring is on the way.春天快到了。 I'd better be on my way soon.我最好还是快点儿走。 Radio forecasts said a sixth-grade wind was on the way.无线电预报说将有六级大风。 2、表示:在路上,在行进中。如: He stopped for breakfast on the way.他中途停下吃早点。 We had some good laughs on the way.我们在路上好好笑了一阵子。 3、表示:(婴儿)尚未出生。如: She has two children with another one on the way.她有两个孩子,现在还怀着一个。 She's got five children,and another one is on the way.她已经有5个孩子了,另一个又快生了。 三、by the way的用法

英语比较级和最高级

形容词比较级和最高级的形式 一、形容词比较级和最高级的构成 形容词的比较级和最高级变化形式规则如下 构成法原级比较级最高级 ①一般单音节词末尾加 er 和 est strong stronger strongest ②单音节词如果以 e结尾,只加 r 和 st strange stranger strangest ③闭音节单音节词如末尾只有一个辅音字母, 须先双写这个辅音字母,再加 er和 est sad big hot sadder bigger hotter saddest biggest hottest ④少数以 y, er(或 ure), ow, ble结尾的双音节词, 末尾加 er和 est(以 y结尾的词,如 y前是辅音字母, 把y变成i,再加 er和 est,以 e结尾的词仍 只加 r和 st) angry Clever Narrow Noble angrier Cleverer narrower nobler angriest cleverest narrowest noblest ⑤其他双音节和多音节词都在前面加单词more和most different more different most different 1) The most high 〔A〕mountain in 〔B〕the world is Mount Everest,which is situated 〔C〕in Nepal and is twenty nine thousand one hundred and fourty one feet high 〔D〕 . 2) This house is spaciouser 〔A〕than that 〔B〕white 〔C〕one I bought in Rapid City,South Dakota 〔D〕last year. 3) Research in the social 〔A〕sciences often proves difficulter 〔B〕than similar 〔C〕work in the physical 〔D〕sciences. 二、形容词比较级或最高级的特殊形式:

高中英语的比较级和最高级用法总结

比较级和最高级 1.在形容词词尾加上―er‖ ―est‖ 构成比较级、最高级: bright(明亮的)—brighter—brightest broad(广阔的)—broader—broadest cheap(便宜的)—cheaper—cheapest clean(干净的)—cleaner—cleanest clever(聪明的)—cleverer—cleverest cold(寒冷的)—colder—coldest cool(凉的)—cooler—coolest dark(黑暗的)—darker—darkest dear(贵的)—dearer—dearest deep(深的)—deeper—deepest fast(迅速的)—faster—fastest few(少的)—fewer—fewest great(伟大的)—greater—greatest hard(困难的,硬的)—harder—hardest high(高的)—higher—highest kind(善良的)—kinder—kindest light(轻的)—lighter—lightest long(长的)—longer—longest loud(响亮的)—louder—loudest low(低的)—lower—lowest near(近的)—nearer—nearest new(新的)—newer—newest poor(穷的)—poorer—poorest quick(快的)—quicker—quickest quiet(安静的)—quieter—quietest rich(富裕的)—richer—richest short(短的)—shorter—shortest slow(慢的)—slower—slowest small(小的)—smaller—smallest smart(聪明的)—smarter—smartest soft(柔软的)—softer—softest strong(强壮的)—stronger—strongest sweet(甜的)—sweeter—sweetest tall(高的)-taller-tallest thick(厚的)—thicker—thickest warm(温暖的)—warmer—warmest weak(弱的)—weaker—weakest young(年轻的)—younger—youngest 2.双写最后一个字母,再加上―er‖ ―est‖构成比较级、最高级: big(大的)—bigger—biggest fat(胖的)—fatter—fattest hot(热的)—hotter—hottest red(红的)—redder—reddest sad(伤心的)—sadder—saddest thin(瘦的)—thinner—thinnest wet(湿的)—wetter—wettest mad(疯的)—madder—maddest 3.以不发音的字母e结尾的形容词,加上―r‖ ―st‖ 构成比较级、最高级:able(能干的)—abler—ablest brave(勇敢的)—braver—bravest close(接近的)—closer—closest fine(好的,完美的)—finer—finest large(巨大的)—larger—largest late(迟的)—later—latest nice(好的)—nicer—nicest ripe(成熟的)—riper—ripest

The way的用法及其含义(一)

The way的用法及其含义(一) 有这样一个句子:In 1770 the room was completed the way she wanted. 1770年,这间琥珀屋按照她的要求完成了。 the way在句中的语法作用是什么?其意义如何?在阅读时,学生经常会碰到一些含有the way 的句子,如:No one knows the way he invented the machine. He did not do the experiment the way his teacher told him.等等。他们对the way 的用法和含义比较模糊。在这几个句子中,the way之后的部分都是定语从句。第一句的意思是,“没人知道他是怎样发明这台机器的。”the way的意思相当于how;第二句的意思是,“他没有按照老师说的那样做实验。”the way 的意思相当于as。在In 1770 the room was completed the way she wanted.这句话中,the way也是as的含义。随着现代英语的发展,the way的用法已越来越普遍了。下面,我们从the way的语法作用和意义等方面做一考查和分析: 一、the way作先行词,后接定语从句 以下3种表达都是正确的。例如:“我喜欢她笑的样子。” 1. the way+ in which +从句 I like the way in which she smiles. 2. the way+ that +从句 I like the way that she smiles. 3. the way + 从句(省略了in which或that) I like the way she smiles. 又如:“火灾如何发生的,有好几种说法。” 1. There were several theories about the way in which the fire started. 2. There were several theories about the way that the fire started.

(完整版)初中英语比较级和最高级的用法

英语语法---比较级和最高级的用法 在英语中通常用下列方式表示的词:在形容词或副词前加more(如 more natural,more clearly )或加后缀 -er(newer,sooner )。典型的是指形容词或副词所表示的质、量或关系的增加。英语句子中,将比较两个主体的方法叫做“比较句型”。其中,像“A比B更……”的表达方式称为比较级;而“A最……”的表达方式则称为最高级。组成句子的方式是将形容词或副词变化成比较级或最高级的形态。 一、形容词、副词的比较级和最高级的构成规则 1.一般单音节词和少数以-er,-ow结尾的双音节词,比较级在后面加-er,最高级在后面加-est; (1)单音节词 如:small→smaller→smallest short→shorter→shortest tall→taller→tallest great→greater→greatest (2)双音节词 如:clever→cleverer→cleverest narrow→narrower→narrowest 2.以不发音e结尾的单音节词,比较在原级后加-r,最高级在原级后加-st; 如:large→larger→largest nice→nicer→nicest able→abler→ablest 3.在重读闭音节(即:辅音+元音+辅音)中,先双写末尾的辅音字母,比较级加-er,最高级加-est; 如:big→bigger→biggest hot→hotter→hottest fat→fatter→fattest 4.以“辅音字母+y”结尾的双音节词,把y改为i,比较级加-er,最高级加-est; 如:easy→easier→easiest heavy→heavier→heaviest busy→busier→busiest happy→happier→happiest 5.其他双音节词和多音节词,比较级在前面加more,最高级在前面加most; 如:beautiful→more beautiful→most beautiful different→more different→most different easily→more easily→most easily

相关文档
相关文档 最新文档