Language Acquisition PDF

4 Language acquisition Introduction The stages of language acquisition...

4 Language acquisition Introduction The stages of language acquisition Pre-linguistic stage One-word stage Development of grammar Meaning and pragmatics Summary Review exercise Introduction Copyright © 2003. Taylor & Francis Group. All rights reserved. The use of language is an extraordinarily complicated skill. Each of us has the capacity to produce and understand an almost limitless number of sentences. For many people this skill for using language is a defining feature of humanity. Yet this complicated skill seems to be learned by children with no difficulty, and nearly all children who are exposed to language learn it very quickly. There are a large number of studies of language development in children. Some of this research is cross-sectional (studying groups of children of different ages), but due to the complexity of language learning and the variation between children a lot of the work is longitudinal. These are studies of children over a long period of time and typically concentrate on one or two children. The research into the process of language learning has led to a number of theories about 39 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE AND THOUGHT how children learn language. This chapter will focus on the process of language learning and the next will consider theories of how children learn language. The stages of language acquisition There is great variation in language acquisition in children. They vary in the speed they learn, the words they learn, etc. These variations can be biological, social or cultural in origin. However, despite these variations it seems that all children learn language in a number of stages. These stages appear to be universal and apply to all children regardless of the language they are learning or the society they are in. The three main stages that have been identified are the pre-linguistic stage, one-word stage and development of grammar (starting with two-word stage). There are two things to bear in mind when looking at stages of language development. Firstly, the transition from one stage to the next is very gradual. A child who starts to use two-word sentences will carry on using one-word utterances for some time. Secondly, because of the variation at which children learn language, the ages given for each stage are a very rough guide only. Pre-linguistic stage The pre-linguistic stage is the time before children start to use their first words and lasts from birth to approximately 12 months old. Although children of this age do not use language this is an important Copyright © 2003. Taylor & Francis Group. All rights reserved. stage for both comprehension and production of language. A large number of studies have shown that infants are very sensitive to the sounds made in speech and are able to distinguish between similar consonant or syllable sounds from as little as 1 month old. For example, Eimas et al. (1971) found that 1-month-old infants were able to differentiate between a ‘pa’ and ‘ba’ sound. Initially infants do not use a wide range of sounds and until about 2 months old the principal sound they produce is crying. Infants do communicate using crying and parents become skilled at determining different types of cry. At about 2 months old infants add a different type of sound to their repertoire which is called cooing. These are vowel sounds such as ‘oooo’ which vary in tone and volume. Cooing is typically associated with pleasure. 40 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE ACQUISITION A major development in the production of speech sounds occurs at about 6 months when infants start to produce sounds which combine vowels and consonants (e.g. ‘ga’ or ‘ba’). The production of these sounds is called babbling and this accounts for a large part of the infant’s vocalisation from 6 months through to the production of words. The onset of babbling and the types of sounds produced seem to be universal and are similar regardless of culture or of whether the child can hear or not. This suggests that babbling is the result of matura- tional processes rather than learning. However, there is evidence that infants learn from the sounds they hear because after about 10 months the range of sounds produced is influenced by the sounds of the language the infant hears (de Boysson-Bardies et al., 1984). Infants stop using some of the sounds that they do not hear but carry on using sounds they do hear. Deaf infants tend to stop babbling, presumably because of a lack of feedback. Another feature of babbling at about 10 months is that infants often string lots of babbling sounds together (e.g. ‘dadadada’), a characteristic known as echolalia. Sequences of echolalia sometimes show intonational patterns which appear speech- like although the infant does not use any words. These patterns reflect the intonational patterns of the language the infants are exposed to (Bee, 2000). There is a question about how much infants learn about speech production during this phase, but at the very least they seem to learn how to control their vocal tracts and how to produce relevant sounds (Clark and Clark, 1977). There is also evidence that infants understand many words before they are able to produce them (Bee, 2000). This is Copyright © 2003. Taylor & Francis Group. All rights reserved. a feature of all the early stages of language development; the ability to understand speech (receptive language) exceeds the ability to pro- duce speech (expressive language). Another feature of the pre-linguistic stage is that at about 9 months old infants start to communicate using gestures. An infant who points to a toy and makes grasping movements of the hand is clearly ‘asking’ for the toy (the persistence of the gesture and the loud noise that ensues if the ‘request’ is not met leave little room for doubt!). One-word stage The one-word stage typically starts at about 12 months old. At this age the majority of vocalisation is still babbling, but children start 41 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE AND THOUGHT to use words amongst the babbling. Often these early words are not like the adult versions of the word but are approximations of them. Some early words may be totally different to adult versions, but they are regarded as ‘words’ provided they are used consistently to refer to a specific object or action. For example, Scollon (1976) studied a child named Brenda, one of whose first words was ‘nene’ which, although bearing little relationship to adult English, was used consistently to refer to anything that was in a feeding bottle (milk, juice, etc.). After producing the first word the rate of acquisition of new words is initially very slow. For example, one study found that it took 3–4 months after the first word before a further ten words were added (Nelson, 1973). However, at some point between 16 and 18 months children start to acquire new words much more rapidly. Harley (2001) has called this the ‘vocabulary explosion’ and notes that it coincides with a number of other major language developments such as the production of two-word sentences (see p.43, this volume). The estimates of how many words children produce from 12 months onwards vary greatly and probably reflect the variation amongst children, but typically at 18 months children have a vocabulary of 50 words and at 24 months 300 words. Although there is variation in the actual words that children learn there seems to be a consistent pattern in the types of words they learn. Nelson (1973) found that children’s vocabularies in the one-word stage could be classified into six categories, including general nominals (names of objects, e.g. bottle), specific nominals (names unique to people or animals, e.g. Copyright © 2003. Taylor & Francis Group. All rights reserved. Fido), and action words (describing action, e.g. look). She found that over half the words children use are general nominals; subsequent studies suggest this is a trend in many languages, including Japanese, Chinese, German and Turkish. Many early words are often context- bound and may be used in certain situations only. For example, Bloom (1973) described a child who only used the word ‘car’ to describe cars seen from one location. Although children initially communicate using single words they are able to convey a variety of messages with each word. The message the word conveys may change according to the context in which it is used, the tone in which it is said and the gestures that accompany it. For example a child may use the sound ‘di’ to refer to a doll. If the word is used with a rising voice whilst pointing to 42 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE ACQUISITION the doll across the room it suggests a request for the doll. The use of single words to convey a variety of messages is known as using holo- phrases. Progress exercise Think of how a child might indicate the following phrases using just one word: This is my juice. I want some juice. I’ve spilt my juice. What other cues would the child use apart from the word itself? Development of grammar At about 18 months old children start to produce two-word sen- tences. This two-word stage marks the development of syntax (or the grammatical rules of how to combine words). Once they start to combine words children learn grammar very quickly and pass through a number of phases that are characterised by increasing complexity of the grammar and sentence length. Although initially children may use single-word holophrases and some two-word sentences they soon start to use three, then four words, and so on. Psycholinguists use a measure called the mean length of utterance (MLU) to record the average number of words children use in their sentences. Copyright © 2003. Taylor & Francis Group. All rights reserved. Of course, children continue to add to their vocabulary during this stage and studies show that the rate of word acquisition in pre-school children is remarkable. At the age of 2 children have a vocabulary of about 300 words, but by the age of 6 this increases to an average of 13,000 words. Early grammar The use of early grammar, which Brown (1973) called ‘Stage 1 grammar’, typically lasts from 18 to 30 months (although the transition to later stages is difficult to pinpoint). Sentences during this phase show two main characteristics: they are short and they are simple. Most sentences during this phase are two or three words long and consist 43 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE AND THOUGHT of only the essential words to convey meaning (nouns, verbs and adjectives). Many features of adult language are not used. For example, a child may say ‘Play doll’ instead of ‘I am playing with the dolls’. This type of speech has been described as telegraphic because, like a telegraph, it uses only the critical words in the sentence (Brown, 1973). Inflections, such as the auxiliary verb ‘am’ or the plural ‘s’, are omitted. Although these early sentences are short and simple they seem to be created using rules (or grammar). Owens (2001) suggests that children may experiment with a variety of rules as they start to combine words but eventually use word-order rules such as action + object (e.g. ‘drink milk’). These grammatical rules may not be the same as those used by adults but most research suggests that they are used consistently. Thus, although there is not complete agreement about the nature of the early grammar, there seems to be agreement that children use some form of rules for word position. Bee (2000, p.236) claims ‘there is no dispute about the assertion that even at this earliest stage children create sentences following rules’. Later grammar At about 30 months children start to use more complex grammar and begin what has been called a ‘grammar explosion’ (Bee, 2000). The length of the sentences (the MLU) gradually gets longer and children start to add both inflections and functional words. Brown (1973) calls the use of more elaborate grammar ‘Stage 2 grammar’. Copyright © 2003. Taylor & Francis Group. All rights reserved. In English one of the first inflections to be added is the verb ending ‘ing’ (e.g. playing), followed by articles (a and the) and later adding ‘s’ to indicate a plural (e.g. dogs). Children also start to use different forms of sentences such as negatives and questions, although the initial form may not be exactly the same as adult language. For example when children first produce negative sentences they often omit the auxiliary verb so they might say ‘I not playing’ instead of ‘I am not playing’ (Bloom, 1991). There is evidence that children learn rules of grammar rather than simply imitate adult speech. One source of evidence comes from studies of overregularisation. This occurs when regular rules of grammar are applied to irregular examples. For example, adding ‘ed’ to the end creates the past tense of many verbs (e.g. laughed, played) 44 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE ACQUISITION – but this is not the case for all verbs. However, children often overregularise and say ‘goed’ instead of ‘went’ or ‘singed’ instead of ‘sang’. This is also evident in the use of plurals, which are typically produced by adding an ‘s’. Children misapply this rule and will say words like ‘sheeps’ or ‘foots’. Another common type of overreg- ularisation occurs in the use of superlatives (as in big, bigger and biggest). Children often misapply the regular rule to the word ‘bad’ and say ‘badder’ and ‘baddest’ instead of worse and worst. Since children will not hear adults using words like ‘goed’ or ‘badder’ it seems that they have learned a rule and are misapplying it. There is also experimental evidence that children learn general language rules. In a famous study Berko (1958) showed children a picture of a fictitious creature called a ‘wug’ (see Figure 4.1). The children were told ‘This is a wug’ and then were shown a picture of two of the creatures. After explaining that there was now another wug, the children were asked to complete the sentence ‘There are two... ’ The children responded by saying ‘wugs’. This clearly shows the Here is a wug. Copyright © 2003. Taylor & Francis Group. All rights reserved. Now there is another one. There are two ________ Figure 4.1 An experiment to test whether children use rules of grammar (based on Berko, 1958; courtesy of Jean Berko Gleason) 45 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE AND THOUGHT application of a rule since the children had never come across a wug before and could not have heard anyone else say ‘wugs’. Language gradually becomes more and more complex in pre- school children. The length of sentences tends to increase and children become able to add ideas together by using conjunctions such as and. By the age of about 5 years children tend to learn most of the grammar they will use as adults. However, there are some forms of sentences that are not learned until later. For example 5-year-old children do not use many passive sentences such as ‘The cat was chased by the dog.’ Furthermore, they can be confused about the meaning of passive sentences, and in the example given they are likely to think that it was the cat that did the chasing. However, adults rarely use passive forms of sentences and it is unlikely that children hear many passive sentences. Meaning and pragmatics The discussion in this chapter so far has concentrated on the use of words and production of sentences. There are two other important aspects of learning a language however: developing an understanding of word meaning and using language to communicate with others (pragmatics). Meaning One of the fundamental questions about language is how do children Copyright © 2003. Taylor & Francis Group. All rights reserved. develop an understanding of word meaning? In other words, how do children learn that one particular set of sounds refers to a category of objects or type of action? Initially this seems a simple task to explain; parents use words when objects appear or actions occur. However, take the example of a cat chasing a ball across a room and a parent pointing and saying ‘cat’. How does the child know the word refers to the cat? It could refer to something else in the scene (e.g. the ball); it could refer to part of the cat (e.g. the tail); it could refer to a property of the cat (e.g. furriness); or it could refer to something the cat is doing (e.g. running). It is not known exactly how children learn the meaning of words but their behaviour suggests that a number of assumptions or principles are used. Owens (2001) suggests that three of these principles seem to be fundamental to learning word meaning. The first of these, 46 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE ACQUISITION the reference principle, is that words refer to things (i.e. the word ‘cat’ refers to an animal). Initially this principle is accompanied by the mutual exclusivity assumption or the assumption that a word refers to one class of object only (i.e. the word ‘cat’ can only refer to the animal and not something else as well such as the ball). The second principle is the extendability principle, which is the assumption that words refer to a class of objects not a unique object (i.e. the word ‘cat’ refers to all cats not just one cat). The third principle is the whole- object principle, which is that words refer to the whole object not just parts of it (i.e. the word ‘cat’ refers to the whole animal not the tail). Learning the words that refer to the constituent parts is a later development. Finally, Owens (2001) also notes that children do not simply learn the meaning of words by exposure to them but are actively engaged in trying to understand adult language and to make asso- ciations between words and objects. Another question about learning word meaning is whether children develop a concept about a category first and then the word to describe that category, or whether they learn a word and then the category to which it applies. In other words, does a child discover that there is a group of objects that are furry, have four legs and which bark and then find that there is a word, ‘dog’, to describe this group or does the child learn the word ‘dog’ and then find it applies to furry, four-legged objects that bark? (See Chapter 2 about the relation- ship between language and thought.) There seems to be evidence that both occur, sometimes children learn the concept then the word, but sometimes they learn the word then the concept (Bee, 2000). For Copyright © 2003. Taylor & Francis Group. All rights reserved. example, there is evidence that children cannot use some words accurately until they have developed the appropriate concept (see p.22). On the other hand there is also evidence that when children learn a new word it suggests to them that another category exists (Waxman and Hall, 1993). Pragmatics Another vital aspect of language learning is the use of language to communicate with others – pragmatics. There is growing interest in this aspect of language and it lies at the heart of some theories of language learning (see p.61). Children learn some communi- cation skills at an early age but others take more time to develop. For 47 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE AND THOUGHT example, children learn the communication skill of turn-taking by 18 months. They are able to use the non-verbal signals of shifting eye gaze to indicate the beginning and end of utterances (Bee, 2000). The use of different types of speech for different audiences comes later, but by the age of 4 children use different speech for adults than they use with younger children. They use a simpler form of language, or ‘motherese’ (see p.54) with younger children. Most of the skills used in communicating with others are learned by the age of 5. Summary Language development occurs in a series of stages. The first stage is the pre-linguistic stage and it lasts from birth to approximately 12 months old. Initially the only sounds infants make is when crying, but within a few weeks they begin cooing. At about 6 months old infants begin babbling. These are vowel and consonant sounds that account for a large part of the infant’s vocalisation until the infant begins to use words. The production of words, typically at 12 months old, marks the transition to the next stage, the one-word stage. Acquisition of new words is slow at first and most of these tend to be general nominals (nouns). Children are able to convey a variety of meanings using single words by changing tone or using gestures. The use of single words in this way is called holophrases. Acquisition of new words is initially slow but shortly before 18 months old there is a rapid acceleration that is followed by the emergence of two-word sentences. The use of two-word sentences marks the start of grammar development since Copyright © 2003. Taylor & Francis Group. All rights reserved. the child uses rules to combine the words. Early sentences are described as telegraphic speech because they use only the essential words to communicate meaning. At approximately 30 months old children start to use more complicated grammar and longer sentences. Most of the grammatical rules used as adults are learned by the age of 5, although the use of language continues to become more complex during childhood. Two other important aspects of language are the acquisition of word meaning and pragmatics. Learning of word meaning seems to follow a number of basic principles and involves an active attempt by children to connect words with referents. The skills needed to communicate with others, or pragmatics, are apparent in early childhood and, like grammatical rules, most are learned by the age of 5. 48 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  LANGUAGE ACQUISITION Each box beside the timeline below represents the approximate age for the Review exercise emergence of an aspect of vocalisation or language. Use the chapter to fill in each box 0 6 months 12 months 18 months 24 months 30 months Further reading Bee, H. (2000) The Developing Child (9th edn). New York: Longman. This well-known developmental psychology textbook has an Copyright © 2003. Taylor & Francis Group. All rights reserved. excellent chapter on the development of language. Owens, R.E. (2001) Language Development: an introduction (5th edn). Needham Heights, Mass: Allyn and Bacon. This is a detailed but accessible book on language development. It covers the whole process of language development thoroughly and deals with a variety of other aspects such as bilingualism and language disorders in children. The American Speech Language Hearing Association has an excellent online site that deals with language development, bilingualism and activities to encourage speech and language development in children: www.asha.org/speech/development 49 Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.  This page intentionally left blank Copyright © 2003. Taylor & Francis Group. All rights reserved. Lund, Nick. Language and Thought, Taylor & Francis Group, 2003. ProQuest Ebook Central, http://ebookcentral.proquest.com/lib/cityuhk/detail.action?docID=199320. Created from cityuhk on 2024-10-29 07:21:23.