The main objective of this paper is to describe the trajectory of Danish children's early lexical development relative to other languages, by comparing a Danish study based on the Danish adaptation of The MacArthur-Bates Communicative Development Inventories (CDI) to 17 comparable CDI-studies. The second objective is to address the feasibility of cross-linguistic CDI-comparisons. The main finding is that the developmental trend of Danish children's early lexical development is similar to trends observed in other languages, yet the vocabulary comprehension score in the Danish children is the lowest across studies from age 1 ; 0 onwards. We hypothesize that the delay is related to the nature of Danish sound structure, which presents Danish children with a harder task of segmentation. We conclude that CDI-studies are an important resource for cross-language studies, but reporting of studies needs to be standardized and the availability of published data improved in order to make comparisons more straightforward.

The current study examines the syntactic and prosodic characteristics of the maternal speech to two infants between six and ten months. Consistent with previous work, we find infant-directed speech to be characterized by generally short utterances, isolated words and phrases, and large numbers of questions, but longer utterances are also found. Prosodic information provides cues to grammatical units not only at utterance boundaries, but also at utterance-internal clause boundaries. Subject–verb phrase boundaries in questions also show reliable prosodic cues, although those of declaratives do not. Prosodic information may thus play an important role in providing preverbal infants with information about the grammatically relevant word groupings. Furthermore, questions may play an important role in infants' discovery of verb phrases in English.

The objectives were to explore the often reported noun advantage in children's language acquisition using a picture naming paradigm and to explore the variables that affect picture naming performance. Participants in Experiment 1 were aged three and five years, and in Experiment 2, five years. The stimuli were action and object pictures. In Experiment 1, action pictures produced more errors than object pictures for the three-year-olds, but not the five-year-olds. A qualitative analysis of the errors revealed a somewhat different pattern of errors across age groups. In Experiment 2 there was no robust difference in accuracy for the actions and objects but naming times were longer for actions. Across both experiments, imageability was a robust predictor of object naming performance, while spoken frequency was the most important predictor of action naming. The results are discussed in terms of possible differences in the manner in which nouns and verbs are acquired.

Researchers have long noted that children's grammatical morphemes are variably produced, raising questions about when and how grammatical competence is acquired. This study examined the spontaneous production of determiners by two French-speaking children aged 1 ; 5–2 ; 5. It found that determiners were produced earlier with monosyllabic words, and later with disyllabic and trisyllabic words. This suggests that French-speaking children's early determiners are prosodically licensed as part of a binary foot, with determiners appearing more consistently only once prosodic representations become more complex. This study therefore provides support for the notion that grammatical morphemes first appear in prosodically licensed contexts, suggesting that some of the early variability in morphological production is systematic and predictable.

This study investigates when and how French-learning children acquire the main grammatical constraint on the noun category, i.e. the obligatory use of a preceding determiner. Spontaneous speech samples coming from the corpora of twenty children in each of three age groups, 1 ; 8, 2 ; 6, 3 ; 3, were transcribed and coded with respect to morphosyntactic, lexical and length properties of nouns. Results indicate that noun grammaticalization is a gradual process which involves early transitional procedures, as well as an increasing diversity in the content and contexts of determiner use. In support of prosodic hypotheses, noun length effects (in favor of monosyllabic nouns) mostly occurred at 1 ; 8. Animacy effects supporting the lexical hypothesis (in favor of inanimate nouns) occurred at 2 ; 6 and 3 ; 3. We suggest that noun grammaticalization is influenced by both prosodic and lexical factors. Prosodic influences predominate in the first steps of the developmental process, while lexical influences emerge in later steps.

Children pass through a stage in development when they produce utterances that contain auxiliary BE (he's playing) and utterances where auxiliary BE is omitted (he playing). One explanation that has been put forward to explain this phenomenon is the presence of questions in the input that model S-V word order (Theakston, Lieven & Tomasello, 2003). The current paper reports two studies that investigate the role of the input in children's use and non-use of auxiliary BE in declaratives. In Study 1, 96 children aged from 2 ; 5 to 2 ; 10 were exposed to known and novel verbs modelled in questions only or declaratives only. In Study 2, naturalistic data from a dense database from a single child between the ages of 2 ; 8 to 3 ; 2 were examined to investigate the influence of (1) declaratives and questions in the input in prior discourse, and (2) the child's immediately previous use of declaratives where auxiliary BE was produced or omitted, on his subsequent use or non-use of auxiliary BE. The results show that in both the experimental and naturalistic contexts, the presence of questions in the input resulted in lower levels of auxiliary provision in the children's speech than in utterances following declaratives in the input. In addition, the children's prior use or non-use of auxiliary BE influenced subsequent use. The findings are discussed in the context of usage-based theories of language acquisition and the role of the language children hear in their developing linguistic representations.

Two studies test the hypotheses that individual differences in phonological memory among children younger than two years can be assessed using a non-word repetition task (NWR) and that these differences are related to the children's rates of vocabulary development. NWR accuracy, real word repetition accuracy and productive vocabulary were assessed in 15 children between 1 ; 9 and 2 ; 0 in Study 1 and in 21 children between 1 ; 8 and 2 ; 0 in Study 2. In both studies, NWR accuracy was significantly related to vocabulary percentile and, furthermore, uniquely accounted for a substantial portion of the variance in vocabulary when real word repetition accuracy was held constant. The findings establish NWR as a valid measure of phonological memory in very young children, and they open the door for further studies of the role of phonological memory in early word learning.

This paper presents a large-scale cross-sectional study of Danish children's early language acquisition based on the Danish adaptation of the MacArthur-Bates Communicative Development Inventories (CDI). Measures of validity and reliability imply that the Danish adaptation of the American CDI has been adjusted linguistically and culturally in appropriate ways which makes it suitable for tapping into Danish children's language acquisition. The study includes 6,112 randomly selected children in the age of 0 ; 8 to 3 ; 0, and results related to the development of early gestures, comprehension and production of words as well as grammatical skills, are presented.

Two recent papers (de Villiers & Johnson, 2007; Johnson, de Villiers & Seymour, 2005) have claimed that children have difficulty with verbal -s until five–six-years-old. This contrasts with perceptual studies showing evidence for sensitivity to the grammatical properties of verbal -s as young as 1; 4. These apparently conflicting findings can be reconciled by differentiating between early perceptual grammatical knowledge and later semantic comprehension.

This study examined information about adjective meanings available in adults' spoken discourse in the original 27 CHILDES corpora of typically developing English-speaking children. In order to increase the probability that adjectives would be novel to children to whom they were addressed, only rare adjectives were examined (those that occurred ⩽5 times in the corpus, N=878). Contexts surrounding adjectives (±3 utterances on either side of the target) were scored for linguistic clues to meaning, including related language, compare/contrast and evaluative information. Linguistic contexts contained more information in adult–child conversations than in adult–adult conversations. There were differences among information categories. For example, explicit definitions were relatively rare compared to other types of information and were far less frequent than reported in structured laboratory situations. Findings highlight the importance of looking at adult input in situations where teaching word meaning is not an explicit goal.

Fikkert (1994) analyzed a large corpus of Dutch children's early language production, and found that they often add targetless syllables to their words in order to create bisyllabic feet. In this note we point out a methodological problem with that analysis: in an important number of cases, epenthetic vowels occur at places where grammatical morphemes (e.g. plural and diminutive suffixes) may be expected. Hence, the seemingly targetless syllables may represent grammatical morphemes. A reanalysis of Fikkert's original data reveals that her rhythmic explanation cannot be maintained if those cases are excluded from the analysis.

This article reviews the proliferation of terms that have been coined to denote the language environment of the young child. It is argued that terms are often deployed by researchers without due consideration of their appropriateness for particular empirical studies. It is further suggested that just three of the dozen or more available terms meet the needs of child language researchers in most instances: child-directed speech, infant-directed speech and exposurelanguage. The phenomena denoted by these terms are then considered. The term register is generally borrowed for this purpose from sociolinguistics. However, close inspection of this concept reveals that the notion of register needs to be constrained, in specified ways, in order to be of any real value within the field of child language research.

The study reported here examined the manner in which children represent morphologically complex words in the lexicon. Children in grades 1 to 5 completed a fragment completion task to assess the priming effects of morphologically related words. Both inflected and derived words (e.g. needs and needy, respectively) were more effective primes than control words (e.g. needle) that share similar orthography and phonology with the target word (e.g. need). These effects were consistent across the developmental period studied. Further, equivalent priming effects from the inflected and derived forms suggest that these word types are represented similarly in the developing lexicon.

This study sought to determine why American parents from different socioeconomic backgrounds communicate in different ways with their children. Forty-seven parent–child dyads were videotaped engaging in naturalistic interactions in the home for ninety minutes at child age 2 ; 6. Transcripts of these interactions provided measures of child-directed speech. Children's vocabulary comprehension skills were measured using the Peabody Picture Vocabulary Test at 2 ; 6 and one year later at 3 ; 6. Results indicate that: (1) child-directed speech with toddlers aged 2 ; 6 predicts child vocabulary skill one year later, controlling for earlier toddler vocabulary skill; (2) child-directed speech relates to socioeconomic status as measured by income and education; and (3) the relation between socioeconomic status and child-directed speech is mediated by parental knowledge of child development. Potential mechanisms through which parental knowledge influences communicative behavior are discussed.

This case study is based on the longitudinal data of a girl (LYC, 1 ; 2–3 ; 3) acquiring Taiwan Southern Min (TSM) as her first language, and it aims to discover the overgeneralization pattern of children acquiring causatives in TSM. Among the three types of causative, the errors found in other languages are mostly with lexical causatives; however, in TSM, the errors occur with morphological and analytic causatives. Being an analytic language, TSM tends to spell out the causative meaning through morphological and analytic causatives and thus most errors occur with these two types. In contrast, lexical causatives, which contain a semantic element CAUSE, were acquired late; in the data collected (1 ; 2–3 ; 3) lexical causatives were not yet found. This case study provides evidence from TSM to show a different overgeneralization pattern.

The Macarthur-Bates Communicative Development Inventories (CDI) have been used widely to document early communicative development. The paper reports on a large community sample of 1,447 children recruited from low, middle and high socioeconomic (SES) areas across metropolitan Melbourne, Australia. Regression analyses were conducted to determine the extent to which communicative behaviours reported at 0 ; 8 and 1 ; 0 predicted vocabulary development at 1 ; 0 and 2 ; 0. In support of previous findings with smaller, often less representative samples, gesture and object use at 1 ; 0 were better predictors of 2 ; 0 vocabulary than were gesture and object use at 0 ; 8. At 1 ; 0, children from the lower SES groups were reported to understand more words than children from the higher SES groups, but there were no SES differences for words produced at 1 ; 0 or 2 ; 0. The findings add to our understanding of the variability in the development of early communicative behaviours.

We found that infant gaze following and pointing predicts subsequent language development. At ages 0 ; 10 or 0 ; 11, infants saw an adult turn to look at an object in an experimental setting. Productive vocabulary was assessed longitudinally through two years of age. Growth curve modeling showed that infants who gaze followed and looked longer at the target object had significantly faster vocabulary growth than infants with shorter looks, even with maternal education controlled; adding infant pointing strengthened the model. We highlight the role of social cognition in word learning and emphasize the communicative-referential functions of early gaze following and pointing.

Children with word finding difficulties (CwWFDs) are slower and less accurate at naming monomorphemic words than typically developing children (Dockrell, Messer & George, 2001), but their difficulty in naming morphologically complex words has not yet been investigated. One aim of this paper was to identify whether CwWFDs are similar to typically developing children at producing inflected (morphologically complex) words. A second aim was to investigate whether the dual-mechanism model could account for the use of morphology in a sample of CwWFDs, exemplifying the notion that regular inflections are part of a rule-based system and computed on-line, while irregular inflections are retrieved directly from the associative system (Pinker, 1999). The inflectional knowledge of a group of CwWFDs was compared against a group of language age-matched typically developing peers in three experiments. In Experiment 1 children produced the past tenses of high- and low-frequency regular and irregular English verbs. In Experiment 2 children generalized their knowledge of the past tense system onto nonsense verbs and in Experiment 3 children produced past tenses of verbs used in either a denominal or a verb root context. In each of these three studies, the CwWFDs performed similarly to matched typical children, suggesting that they do not have a selective problem with morphosyntactic features of words. The findings provide mixed support for the dual-mechanism model.