babble balanced bilingualism ere) acd critical period Perey een high amplitude sucking Pee eee vr) Lass ee ered eee ess rar eer ree Cert processing Pero poverty of the stimulus ty ea vocabulary spurt Child language acquisition KENDALL A. KING eats ae Al How children acquire language has long intrigued scholars and nonscholars alike. Parents of young children are often amazed at how quickly their babies move from cooing and babbling to forceful one- and two-word demands. Linguists and psychologists, in turn, have been interested in understanding the stages and mechanisms by which all children become competent users of language (or, in most of the world, languages) by age three or four. Indeed, children from all backgrounds, and under diverse learning conditions, tend to pass through similar phases in learning their mother tongues. Researchers are interested in exploring this process to gain a better understanding of how children accomplish this remarkable feat, but also because the nature of these process- es holds important implications for larger debates in the field of linguistics. Understanding the mechanisms of how children acquire their language(s) can shed important light on the nature of language, as well as on the nature of human learning. This chapter will first explore how researchers gather data on child language acquisition. We will review three approaches to child language acquisition research: parental diaries, observational studies, and experimental studies. After briefly discussing the advantages and disadvantages of these research approaches, we'll tum to the actual data. Specifically, we will look at the major milestones of language development in phonology, semantics, morphology, and syntax. We'll also examine the extent to which these processes differ depending on the cultural context and the language being acquired. Lastly, after reviewing some of the major research findings, we will consider how researchers explain these data, outlining the major theoretical positions in the hotly debated field of child language acquisition. cas BOAT R OT eeChild language acquisition GOALS The goals of this chapter are to: + introduce the main research methods for investigating child language acquisition + describe the milestones of child language development + provide an overview of crosslinguistic and crosscultural aspects of child language acquisition + analyze the major theories employed to explain child language acquisition How can we best study how children learn to use language? Because our research subjects are so young, traditional means of data collection are { often inadequate. We cannot, for instance, ask a one-year-old to judge the grammaticality of a sentence. Children’s language comprehension skills generally outpace their production abilities, so relying on children’s ver- bal output alone provides only a partial picture of the acquisition process. Furthermore, recent research suggests that language learning begins even before birth: for instance, infants show a preference for the sounds of their mother’s native language just days after being born, thus indicating that some kind of language learning has taken place in utero, long before sub- jects can serve as research participants in most studies. In collecting and analyzing child language, researchers often strive for { naturalness and representativeness in their data, Natural data are simi- lar to the language children use in everyday life with familiar conversa- tional partners (like the child’s parents) in familiar contexts (like the home) doing routine activities (like playing). Representativeness refers to two goals: first, the language data collected from a particular child should be representative of the language used by that child every day. Thus, if a bilingual child normally speaks mostly Spanish with hisyher mother, a sample of English conversation between the mother and child would not be representative of their everyday interactional patterns. Second, the children studied should be representative of the general population under investigation ~ for example, Spanish-English bilingual four-year olds. Below, three approaches to collecting child language data are briefly described and critiqued in terms of naturalness and representativeness. Parental diaries Some of the earliest studies of child language acquisition are found in par ents’ detailed descriptions of their children’s language development, gen- erally referred to as parental diaries. While early attempts date as far back as the eighteenth century, most parental diaries, such as those of Charles Darwin, come from the late nineteenth and first half of the twentieth century. The most famous of these is Werner Leopold's four-volume account of his daughter Hildegarde’s simultaneous acquisition of GermanChild language acquisition 207 and English. Leopold was a German-English bilingual of German ances- try; his wife was an American with German roots, but English was her dominant language. Leopold kept meticulous notes beginning at Hildegarde’s eighth week of life, with most of the data focusing on her first two years. He also theorized extensively in his diaries and described his working hypotheses on her language development. Leopold's diaries provide rich details and important insights into the process of language learning in general as well as bilingual language acquisition in particular; however, they suffer from many of the short- ‘comings of all parental diary studies. An inherent problem in this type of research is the fact that a diary consists of one observer who is taking notes on just one child, raising the question of whether Hildegarde is represen- tative of all children. Furthermore, the only linguistic forms described in great detail are the utterances that Hildegarde directed at Leopold or which she used around Leopold, providing a potentially limited and unrepresentative sample, There are probably errors and omissions in tran- scription, compounded by the fact that there were no audiotapes of the data, Pethaps more importantly, there is a natural tendency for the parent (or any observer) to selectively focus on outoftheordinary (and more interesting) samples rather than on routine and everyday utterances, ‘Thus, while Leopold’s diary remains a classic in the field, it provides just ‘one particular vantage point on the language acquisition process, a van- tage point which is privileged in terms of the data's naturalness (as Hildegard spoke freely in the company of her own father), but limited in terms of its representativeness. Observational studies Starting in the early 1960s, researchers began to audio record and tran- scribe the everyday speech of children in order to understand how they learned to comprehend and produce basic English sentence structures, Some of the earliest and best-known of these observational studies are those of Roger Brown, who directed a research project at Harvard University which studied the language of three children (from three fam- ilies, none related to Brown) in great detail. Brown's classic book, A First Language: The Early Stages, documents the development of Adam, Sarah, and Eve's language. The book presents some of the first explanations of the development of grammatical and morphological systems over time. Many other observational studies have since been conducted. In these studies, researchers typically audiotape (and more recently also videotape) small number of children (one at a time) interacting in natural contexts regularly over an extended period. These recordings are then transcribed and analyzed. This approach allows researchers to examine, for instance, how questions or past-tense formulations develop over time among dif ferent children, identifying both general patterns and individual differ- ences. Other observational studies of child language, more anthropological in nature, have focused on language socialization practices. These studies attempt to uncover how children are socialized into culturally appropriate208 Child language acquisition FIOURE 6.1 In some cultures, even very young infants are treated as valid conversational partners. language behavior and how linguistic competence develops, with an emphasis on how these patterns of interaction and parents’ ideologies about language vary crossculturally. For instance, in some families, chil- dren are viewed as conversational partners from birth, with cries, grunts, and early babbling sounds treated as meaningful communication attempts (see Figure 6.1). This is far from universal, however; in much of | the world, infants’ early sounds are not assigned any particular meaning } or communicative intent i) Observational studies have tended to be longitudinal - that is, they j have followed the same participants over several months or perhaps as | long as several years. Cross-sectional observational studies, although less ‘common, have also been conducted. These studies record the language behavior of participants from at least two different groups: for instance, a group of two-yearold Korean-American children and a similar group of twoyearold Mexican-American children might be compared in a cross- sectional study. ; Because of the timeintensive nature of collecting, transcribing, and analyzing hours of language data in such close detail, often these obser- vational studies include only small numbers of child participants. Thus,Child language acquisition 209 while observational studies such as these get high marks for providing rel- atively natural data as well as data which are representative of the child's normal speech, it is not always clear to what extent the few participants are representative of the wider population under study. One way researchers have attempted to overcome this drawback has been to share their transcripts. The primary channel for doing so is the Child Language Data Exchange System (CHILDES; see http:|/childes.psy.cmu.edu/). CHILDES has allowed researchers not only to examine acquisition patterns and processes across larger numbers of children, but also to investigate how patterns differ across children from different language groups. Experimental studies Experimental studies constitute a third approach to collecting child lan- guage data. A wide range of methodological approaches falls under this rubric, including those which are more naturalistic in design and those which involve more tightly controlled tests. In general, experimental studies tend to have narrowly defined research questions (for example, at what age can infants recognize their own name or the sound of their mother's voice?) and to use more controlled (and sometimes considered artificial) methods of collecting data, such as the HASP described below. Experimental language data tend to be elicited through carefully designed techniques rather than observed and described as they naturally unfold. Lastly, experimental studies tend to collect less data overall from each participant, but to have a greater number of participants. This means that although the data might be less naturalistic, they have a higher chance of accurately representing the population under study. One of the most widely used experimental procedures to investigate when and how infants begin to make sense of the language around them is the high amplitude sucking paradigm (HASP), This procedure relies on infants’ reactions to stimuli - in particular, the fact that they will suck at a higher rate when presented with novel stimuli. Using a pacifier attached toa machine which records the rate and strength of the infant's sucking, researchers can measure, for instance, whether the infant perceives a dif ference between two similar sounds or two words, such as lice and rice. In order to test this, the infant is given a pacifier and then presented with, for instance, the word lice. At first, the rate of sucking increases, but as lice is presented repeatedly, the infant becomes “bored” with the sound and the rate begins to decline. At this point, rice is presented: if the rate of sucking increases again, researchers interpret this as evidence that the child has detected the new sound and thus can discriminate between lice and rice. If the rate of sucking remains the same, one can assume the child does not distinguish between the two stimuli, This technique can be used with infants who are only a few days old, as all babies are born with a sucking reflex In addition to techniques aimed at measuring auditory discrimination, there are also a number of methods for assessing the production and com- prehension of children’s syntax. For example, in elicited production, a game (for example, with a puppet) or a picture is used to lead children to210 Child language acquisition produce particular sentences. (The “wug” test discussed below is an exam- ple of elicited production.) Another commonly used technique is the truth-value judgment task. Here, the child is presented with a story (typi- cally acted out with puppets or shown with pictures) and then asked to render a yesjno judgment about whether a statement accurately describes what happened in the story. Such techniques have been important in revealing much of what we know about children’s early language abilities, the topic of the following section. All normally developing children, acquiring any of the world’s spoken or signed languages, follow a similar path of language development and reach the major milestones in the same order. However, there is signifi cant variability in the age at which these milestones are reached. The first sounds ‘The techniques described above have yielded much of what we know about infant language ability in the early months, and in particular what we know about the development of speech perception during the first year of life, Speech perception ~ which includes, for instance, the ability to seg: ment the speech stream into meaningful units, to recognize one’s own name in the speech stream, or to distinguish between similar sounding ‘vowels (eg, jee) and joo{)~ isa critical skill that infants develop early in life. ‘These early language skills also involve visual information; for instance, infants as young as two months have been shown to be able to match vowel sounds they hear with the appropriate lip, mouth, and face movements. ‘These early speech perception skills related to the sound structure of lan- guage may help infants to bootstrap into more complex language compe- tencies; bootstrapping refers to the possibility that skills in one area of lan- guage might help the child to develop competencies in other language areas. For instance, infants’ ability to recognize their own names in the speech stream (which appears around the fifth month) may provide them with a means to recognize novel, adjacent words. (See Box 6.1) Box 6.1 How familiar names help babies begin to segment speech How do infants learn to segment the speech stream and to recognize individual words? Bortfeld et al. (2005) provided evidence that infants can exploit familiar words, such as their own names, to segment adja- cent unfamiliar words from a fluent stream of speech. In other words, infants’ names appear to serve as an “anchor” in the speech stream, helping them to disambiguate the words which come just after their name.| Child language acquisition 21 Using the “headturn preference procedure,” the experimenters first familiarized 24 six month-old infants with two sixsentence passages. In one passage, each of the sentences contained the baby's own name followed by a novel word (e.g. “Emma's feet"). Here, fee is the familiarname target. In the other passage, each of the six sentences contained a different name (i.e. not the baby's own) followed by anoth- er novel word (e.g. “Autumn’s cup”). Here, cup is the alternatename target. Infants were paired so that the alternatename passage for one infant was the familiarname passage for another, and vice versa. The researchers then sought to determine whether infants had formed a preference for the familiarname target relative to the alternate-name target (and nonfamiliarized control words) by testing them on each in isolation. Stimuli were presented through loudspeakers located on each side of a testing booth; the dependent variable was how long infants oriented to the side on which the word was being played. Bortfeld and her colleagues found that the infants listened significant- ly longer to the familiar-name target than to the alternatename target, while there was no difference in how long the infants attended to the alternatename targets and the nonfamiliarized controls. Asecond experiment produced similar results, indicating that six- month-old infants likewise displayed a preference for words linked with another familiar name, this time the moniker for their mother (Mommy or Mama), over words linked with an unfamiliar name (Lolly or Lola), Based on these results, the researchers concluded that familiar names provide a useful means for infants to break into a fluent stream of speech and segment out previously unfamiliar words j that follow those names. Early research in speech perception demonstrated that during their ‘ first few months of life, infants are able to discriminate between similar sounds (for example, between /bj and {p)) both in their native language(s) as well as in other languages. Over time, however, infants become more attuned to their native language(s) and less able to make sound distine- tions in other languages. Janet Werker and her colleagues, for instance, working with Hindi- and English-speaking adults and English-learning infants, illustrated that while English-learning infants (six to eight months old) and Hindi-speaking adults could distinguish between the | Hindi sounds of /da/ and Daj, English-speaking adults could not. Her work demonstrated that English-learning infants seem to lose this skill quite quickly, with the sharpest decline in perceptual ability occurring around the end of the first year of life. This line of research underscores the fact that infants are born with the capacity to learn any language in the world, but the capacity to hear like a native fades very early on. ‘The first sound made by all infants is crying. All infants can do this imme- diately from birth; although crying may signal distress, discomfort, bore- om, or other emotions in the first month of life, it is not an intentional _ SeEE ee ~—L 22 Child language acquisition attempt to communicate. From about the second to fifth month, infants tengage in cooing, Coos are generally vowellike sounds which are often interpreted as signs of pleasure and playfulness. ‘All infants begin to babble anywhere between four and six months and generally continue to do so until they reach around one year of age. Babbling is characterized by vowel or consonant-vowel sounds such as ‘ouw-ouw of mama. At this age, infants’ tongues tend to be relatively large compared to the size of their mouths, and as a result, these sounds will often be palatals, such as {y] or fi. Labial sounds such as (b] and [mJ are also common. Babbling begins to conform to the sound patterns of the ‘adults’ language between six and ten months of age, with adult native speakers showing the ability to discriminate the babbles of Chinese, ‘Arabic, English, or French infants, Babbling is seemingly innate and unconscious, but also interactive and social, All infants, including those who are born deaf, go through a peri- od of oral babbling. Deaf infants’ oral babbling tends to consist of a small- er total number of sounds, with certain consonants (e.g. nasals and frica- tives) predominating, Their babbling is random, generally not interactive, and tapers off sooner than that of hearing infants. However, deaf infants who are learning a signed language, such as American Sign Language {ASD also go through a period of "gestural babbling,” which corresponds to signed language and greatly differs from the much more random ges- turing of hearing babies without this exposure. ‘Although there is no meaning (such as a demand for food) associated with this babbling for hearing or for deaf infants, it can be a source of inter- active play. In some cultures, infants are encouraged to continue to babble by caregivers’ smiles or touches, or by their own babbling in return. Infants ‘will often stop babbling in order to listen to their interlocutor (sometimes engaging in giveandtake exchanges known as proto-conversations), and around the fifth month, some infants are able to immediately imitate simple sound sequences presented to them. The first words Sometime around their first birthdays, children begin to assign specific meanings to the sounds they produce. These first words mark the begin= ning of what is known as the holophrastic stage. Holophrastic means ‘characterized by one-word sentences’; infants tend to use single words to communicate a variety of complex functions. For instance, the word mama might be a bid for mother’s attention, a descriptive comment upon seeing mother walk past, or a request for something which mother typically pro- vides, such as food, Through contextual cues, parents often claim to i ‘understand the meaning of these holophrases (engaging in what is some times called “rich interpretation”), although this is difficult to verify empirically. While parents are often very proud of a child who is an early talker, there is little evidence that the timing of the first words corre sponds to later intelligence or age of achievement of other developmental | milestones, (Indeed, Albert Einstein reportedly did not start talking until age three or four!)Child language acquisition 213 Children’s words at this stage tend to be concrete objects which are grounded in and central to everyday experiences and interactions (such as light, tree, water), rather than abstract concepts (peace, happiness). These first words tend to be content words (bear or bed) rather than function words (the, and, on), For children learning English, most first words are nouns. This seems to be related to the fact that sentences in English typically end with nouns, where they are salient, or more noticeable, to learners. This is not the case for children learning all languages, however. For instance, Korean-learning infants’ first words are often verbs; in the Korean lan- guage, verbs are sentencefinal and sentences may consist of only a verb. While working to master the vocabulary around them, children often engage in both semantic overextension and underextension. For instance, a child may overextend the meaning of the word water to include not just drinking water, but also juice, milk, and soda. Underextension, which seems to be less common, refers to the reverse phenomenon: a child, for example, might use baby only to refer to an infant sibling and not to the other babies he]she encounters. Around age two, children enter the two-word stage, characterized by use of phrases which are not more than two words. For English-learning infants, this typically means combining a subject and verb (e.g. baby cry, mama sleep) or a verb and modifier (e.g. eat now, go out). The ordering of these twoword phrases is not fixed, however, and there tends to be limited systematic use of grammatical morphology (for example, the possessive is formed as Miranda bed rather than Miranda's bed), As in many other stages of their linguistic development, children’s capacity for comprehending words outpaces their production ability. For instance, around the age of one, children can typically understand about seventy different words, but only productively use about six. There is about a four: to sixmonth delay between when children can comprehend a given number of words and when they can produce that many words them- selves. Sometime around the end of the second year, children's productive vocabulary begins to develop rapidly; this is sometimes known as the vocabulary spurt, During this period, children begin to add about two hundred words a month to their vocabularies! At approximately two and half years of age, children begin to produce phrases of three or more words, entering the multi-word stage (e.g. Graham go out, Daddy cook dinner, Baby food all gone). Children’s language at this stage has been described as telegraphic speech because, like the eco- nomical language used in telegraphs, it is seemingly direct and makes only limited use of morphological and syntactic markers. First sentences: morphological and syntactic development Many diary, observational, and experimental studies have documented and explored how children become competent users of their language's system of morphology and syntax. From this research, we know that for all languages, both signed and spoken, this process seems to involve the formation of internal “rules”; in other words, children’s increasinglyChild language acquisition regular use of grammatical forms (even non-adultlike or “incorrect” usages such as broked or foots) may reflect children's developing grammat- ical rule systems. We also know that children seem to begin to acquire this grammatical competence at a very young age and, as in vocabulary development, com- prehension skills outpace production. For instance, children who are only seventeen months of age, and typically still producing only one- or two- ‘word utterances, tend to look longer at video clips that correctly corre- spond to the grammar of the oral commentary. For instance, children who hear “The bear sat on the bird” and are shown two pictures (one of a bear sitting on a bird and another of a bird sitting on a bear) will look longer at the picture where the bear is sitting on the bird. This research demon- strates that even at very young ages children are tuned into the semantic significance of their language’s grammatical structures. Research has also demonstrated that morphological and syntactic devel- opment is predictable. In other words, all children follow similar patterns and pass through the same developmental sequences as their competence develops. Although there is some variation depending on the language being acquired, many patterns and processes are constant across different language and cultural groups. Below we focus on these patterns for chil- dren acquiring English; in the following section, we'll highlight some of the crosslinguistic and crosscultural differences that have been docu- mented. ‘The development of inflectional and derivational morphology in chil- dren’s productive language becomes apparent once the child enters the multiple-word stage and continues through age five. The development of inflectional morphology was the focus of early and intensive investiga- tion, Brown's investigation of Adam, Sarah, and Eve, discussed above, made important advances in this area, (See Box 6.2) Box 6.2 Acquisition of grammatical morphemes by Adam, Sarah, and Eve by MLU stage (I-V) and age (year; month) ‘This table presents the stages of acquisition of grammatical forms by three children. Their ages at each stage are presented in italicized parentheses. The first number in the parentheses represents the year and the second the month. Thus 2;3 signifies that the child is two years and three months old. Adam Sarah Eve 3) 13) 106) 16) (2:10) 110139) Present progressive Plural Present progressive Plural Present progressive Past irregular PossessiveChild language acquisition 215 mem) m1 G1) MH (4:11) Uncontractible Uncontractible Plural copula copula Possessive Past irregular Articles Past regular WG2) Vea) WV Q2) Articles ‘Third person Third person regular irregular Possessive V6) van via3) ‘Third person Past regular Uncontractible regular Uncontractible copula Past regular auxiliary Past irregular Uncontractable Contractable Articles auxiliary copula ‘Third person Contractable ‘Third person regular copula irregular ‘Third person. Contractable Contractible |. irregular auxiliary auxiliary Uncontractibie auxiliary Contractible copula Contractible auxiliary Note: Table adapted from Brown (1973). Stages (I-V) correspond to Mean Length of Utterance (MLU): stage I, MLU MLU = 5 .75; stage Il, MLU = 2.25; stage III, MLU = 2.75: stage IV, stage V, MLU = 4. Acquisition of a grammatical form was defined as three successive samples in which the morpheme appears at least 90 percent of the time in obligatory contexts. ‘To calculate the MLU, count the first 100 utterances of a transcribed sample of a child’s language. Next, count the number of morphemes in each utterance and then add up the number of morphemes in all of the 100 utterances. Finally, divide this total by 100 to get the Mean Length of Utterance. If you don’t have 100 utterances, count the num- ber of utterances you have and divide the total number of morphemes by the number of utterances (adapted from Brown 1973), Count cate- natives (eg. wanna, doncha) as one morpheme. Also, don't count fillers (um, of) or sounds (aack, etc.). ‘Through analysis of Adam, Sarah, and Eve's spontaneous speech, Brown mapped out when different grammatical morphemes consistently appeared in their speech and how this corresponded to other aspects of their language, in particular to mean length of utterance (MLU). MLU is a widely used measurement of the complexity of children’s language and is calculated from the average number of morphemes (not words) per utter- ance, Brown illustrated that: (1) the order of acquisition was similar across216 Child language acquisition the three unacquainted children (with present progressive, plural, and past irregular verb forms appearing first); (2) the age at which children acquired competence in using these forms varied widely (compare, for instance, Eve and Adam at age two years and three months in Box 6.2): and (3) the MLU stage served as a good index of the level of development for grammatical morphology (and indeed was much more predictive of gram- matical development than age). More recent research has stressed the importance of vocabulary as a predictor of grammatical development. ‘Another early study which sheds light on when children acquire inflec tional morphology was Jean Berko’s famous “wug” study, Rather than recording and analyzing children’s spontaneous speech as Brown did, Berko asked young children of different ages to form the plural of unknown, non- sense creatures, stich as “wugs.” (See Figure 6.2) The experimenter pointed to an item and said, “This is a wug.” She then showed a picture with the same two animals and said, “Now here is another one. There are two of them. There are two_?" Berko fotind that even preschool children were able to form the plural correctly, demonstrating that they had learned the rule for forming plurals and could apply this rule correctly in novel con- texts, and were not just repeating forms which they had previously heard. In developing these rules, children pass through predictable stages. For instance, children overgeneralize in the early phases of acquisition, meaning that they apply the regular rules of grammar to irregular nouns and verbs. Overgeneralization leads to forms which we sometimes hear in the speech of young children such as goed, eated, foots, and fishes. This process is often described as consisting of three phases: ‘¢ Phase 1: The child uses the correct past tense of go, for instance, but does not relate this pasttense went to present-tense go. Rather, went is treated as a separate lexical item. ‘© Phase 2: The child constructs a rule for forming the past tense and begins to overgeneralize this rule to irregular forms such as go (resulting in forms such as goed). ‘ Phase 3: The child learns that there are (many) exceptions to this rule and acquires the ability to apply this rule selectively. Note that from the observer's or parents’ perspectives, this development is “Ushaped” ~ that is, children can appear to be decreasing rather than increasing in their accuracy of past-tense use as they enter phase 2. However, this apparent “backsliding” is an important sign of linguistic development. ‘We see similar patterns, known as “developmental sequences,” in other areas of grammar, such as the formation of English negatives and inter rogatives. As outlined in Box 63, children move through identifiable stages, although these stages are more continuous and overlapping than discrete, Note that from the parents’ perspective, children’s development is also not always straightforward. For instance, a child will likely produce inverted yesjno questions (Did Karalyn eat cake?), while still using normal declarative word order for WH-questions (How Izzy go out?) (See Chapter 13 for related developmental patterns in second language acquisition.)Child language acquisition 27 This is a wug. Now there is another one. There are two of them. There are two. URE 62. ‘The Wug test28, Child language acquisition Box 63 Development of English negatives and questions {adapted from Akmajian et al. 1995) Stage Negatives Oneword Use of single stage word. No Allgone Early Single negative multiword word occurs stage at start of | sentence only No sleeping No go outside 9i] banana [nena] this {ais} Suggestion for further reading Brown, R. 1973, frst language: the early stages, Cambridge, MA: Harvard University Press. This classic work ‘on fist language acquistion documents the language development of the three young children Adam, Eve, ‘and Sarah in close detail. Har, Band Risley, 7.1995, Meaningful differences in the everyday experience of young American children, Baltimore, MD: Paul H. Brookes. This book, authored by two prominent behaviorist, analyzes family language Use patterns in forty two homes over a two-year period. They report that there were many differences in the uantty and qualty of talk which young children heard in different homes and that these differences were osely linked to significant cifferences in childeen's rate of vocabulary development and 1Q test scores. Lust, B.C and Foley, C. (eds.) 2008, First longuage acquisition: the essential readings, Cambridge, MA: MIT Press. This is a collection of twenty-nine classic papers, mostly dating from the late 1950s to the 1980s. Pinker, 1999, Words and rules: the ingredients of language, New York: Basic Books. This engaging book ‘examines the acquistion and use of regular and irregular verbs in great detail, arguing that the natvist approach is more powerful than connectionist models in fiting and explaining the data234 Child language acquisition Plunkett, K. (ed) 1998, Language acquisition and connectionism, Hove, UK: Psychology Press. This collec- tion of papers from a special issue of Language and Cognitive Processes provides a good overview of lan guage acquisition from a connectionist perspective Slobin, D. |. (ed,) 1985-1997, The crosslinguistic study of language acquisition, vols. 1-5, Hilsdale, NJ: Lawrence Eilbaum. This five-volume set presents studies of language acquisition among children from all ‘over the world. Schieffelin, B. B. 1990, The give and take of everyday life: language socialization of Kalul children, New York: Cambridge University Press. This anthropologically and ethnographicaly oriented book describes and ‘analyzes language socialization and language learning processes among Kaluli children in Papua New Guinea,