This research explores the role of phonotactic probability in two-year-olds' production of coda consonants. Twenty-nine children were asked to repeat CVC non-words that were used as labels for pictures of imaginary animals. The CVC non-words were controlled for their phonotactic probabilities, neighbourhood densities, word-likelihood ratings, and contained the identical coda across low and high phonotactic probability pairs. This allowed for comparisons of children's productions of the same coda consonant in low and high phonotactic probability environments. Children were significantly more likely to produce the same coda in high phonotactic probability non-words than in low phonotactic probability non-words. These results are consistent with the hypothesis that phonotactic probability is a predictor of coda production in English. Moreover, this finding provides further evidence for the role of the input and distribution of sound patterns in the ambient language as a basis for phonological acquisition.

The ability to understand references to the absent enables conversation to move beyond the here-and-now to matters distant in both space and time. Such understanding requires appreciating the relation between language and communicative intent: one must recognize speakers' intentions to use language to converge on a shared conversational focus that is at least somewhat independent of the current context. Despite its centrality to language development, the emergence of absent reference understanding has received little systematic attention. The present research investigated the responses of 60 infants aged 1;0 to 2;6 to a researcher talking about both present and absent caregivers. When infants aged 1;3 and older heard talk about absent caregivers they displayed a complex of nonverbal communicative responses that were divergent from their responses to talk about a present person. Infants aged 2;0 and older provided responses indicating understanding of absent reference. The findings suggest that by 1;3 infants may have at least a tacit appreciation of language as a device for coordinating conversational focus, and hint at increased sophistication in infants' absent reference comprehension skills at 2;0.

When English-speaking two-year-olds begin producing polysyllabic words, they often omit unstressed syllables that precede syllables with primary stress (Allen & Hawkins, 1980; Klein, 1981; Gerken, 1994a). One proposed mechanism for these omissions is that children omit syllables at a phonological level, due to prosodic constraints that act on outputs. Under such accounts, it has been largely assumed that these syllables are simply missing, or deleted, from children's outputs. The present research consists of a pair of experiments that tested this assumption by investigating the acoustic properties of utterances manifesting or lacking weak initial syllable omissions. In the two experiments, 33 two-year-old children were asked to imitate sentences like ‘He kissed Lucinda’ (often reduced as expected to a disyllabic trochaic form, e.g. ‘He kissed _cinda’) and ‘He kissed Cindy’. Durations of each child's imitations were measured from the onset of the verb to the onset of the name, for each pair of sentences containing the reduced or unreduced disyllabic forms, for example, ‘kissed _cinda’ vs. ‘kissed Cindy’. Our results yielded a significantly longer duration for the verb-onset to name-onset portion of sentences containing reduced ‘_cinda’-type names than for sentences with ‘Cindy’-type names. This finding provides evidence that children do not completely delete weak syllables. Rather, the data from the phonetic analysis indicate that some prosodic trace exists of the omitted syllable.

This study examined parental report as a source of information about toddlers' productive vocabulary in 105 low-income families living in either urban or rural communities. Parental report using the MacArthur Communicative Development Inventory – Short Form (CDI) at child age 2;0 was compared to concurrent spontaneous speech measures and standardized language assessments, and the utility of each source of data for predicting receptive vocabulary at age 3;0 (Peabody Picture Vocabulary Test) was evaluated. Relations between language measures of interest and background variables such as maternal age, education, and race/ethnicity were also considered. Results showed that for the sample as a whole, parental report was moderately associated with other language measures at age 2;0 and accounted for unique variance in PPVT at age 3;0, controlling for child language skills derived from a standard cognitive assessment. However, predictive validity differed by community, being stronger in the rural than in the urban community. Implications of significant differences in background characteristics of mothers in the two sites are discussed.

We investigated infant precursors of low language scores in early childhood. The sample included 373 probands in 130 monozygotic (MZ) and 109 same-sex dizygotic (DZ) twin pairs in which at least one member of the pair scored in the lowest 15th percentile of a control sample on a general language factor derived from tester-administered tests at 4;6. From data at 2;0, 3;0 and 4;0 the antecedents of poor language performance at 4;6 for these probands were compared to 290 control children. As early as 2;0, language measures substantially predicted low-language status at 4;6, with predictions increasing at 3;0 and 4;0. Nonverbal cognitive development at 3;0 and 4;0 was nearly as predictive of low language at 4;6 as were the language measures. Behaviour problems were also significant predictors of low language status although the associations were only about half as strong. Bivariate genetic analyses indicated that these predictions are mediated by both genetic and shared environmental links.

The ability to make clear reference in connected discourse was examined in children learning Cantonese, a Chinese language where noun phrase constituents, whatever their grammatical role, are omissible from sentences under discourse conditions that are not well-understood. Forty-three typically developing children aged 3;0, 5;0, 7;0 and 12;0 told 16 stories based on picture sequences. A panel of adult native Cantonese speakers was asked to judge the referential adequacy of each child's stories by identifying the character the child was talking about in 32 targeted referential acts. The targeted acts were of three sorts: MAINTENANCE of a known character, INTRODUCTION of a second new character, and REINTRODUCTION of a known character. Reference was judged to be adequate when 3 out of 4 ‘listeners’ could successfully identify the character. Children's referential expressions were most adequate for Maintenance, less adequate for Introduction, and least adequate for Reintroduction. The twelve- and seven-year-olds approached ceiling on all three functions. The five-year-olds scored poorly on Reintroduction, and the three-year-olds failed both Introduction and Reintroduction, despite knowledge of at least one of the possible linguistic forms required for these acts as evidenced in a sentence imitation task. Viewed within the framework of Levelt's (1989) discourse model, the data improve our understanding of the developmental period during which children learn to make appropriate presuppositions about the listener's knowledge and attentional states.

Comprehension of relative clauses was assessed in 10 Hebrew-speaking school-age children with syntactic SLI and in two groups of younger children with normal language development. Comprehension of subject- and object-relatives was assessed using a binary sentence-picture matching task. The findings were that while Hebrew-speaking children with normal development comprehend right-branching object relatives around the age of 6;0, children with syntactic SLI are still at chance level in object relatives by age 11;0. The four-year-olds were also at chance on object relatives. Comprehension of subject relatives was good in the SLI group, similar to the six-year-olds, and significantly better than the four-year-olds. The syntactic impairment is interpreted as a selective deficit to non-canonical sentences that are derived by movement.

This study examines the production of regular and irregular participle forms of German with high and low frequencies using a speeded production task. 40 children in two age groups (five- to seven-year olds, eleven- to twelve-year olds) and 35 adult native speakers of German listened to stem forms of verbs presented in a sentential context and were asked to produce corresponding participle forms as quickly and accurately as possible. Dependent variables were the subjects' participle-production latencies and error rates. We found contrasts between the production of regular and irregular forms in both children and adults, with respect to the production latencies and types of morphological error. Children overapplied the regular patterns to forms that are irregular in the adult language, but not vice versa. High-frequency irregular participles were produced faster (and amongst the children more accurately) than low-frequency ones, whereas regular participles yielded a reverse frequency effect, i.e. longer production latencies for high-frequency forms than for low-frequency ones, in the two groups of children as well as in one subgroup of adults. We explain these findings from the perspective of dual-mechanism models of inflection arguing that the mental mechanisms and representations for processing morphologically complex words (‘words’ and ‘rules’) are the same in children and adults, and that the observed child/adult differences in participle production are due to slower and less accurate lexical access in children than in adults.

This study examined the on-line processing of French sentences in a grammaticality judgment experiment. Three age groups of French children (mean age: 6;8, 8;6 and 10;10 years) and a group of adults were asked to detect grammatical violations as quickly as possible. Three factors were studied: the violation type: agreement violations (number and gender) vs. word order violations; the violation position: early vs. late in the sentence; the target type of the violations: intra vs. interphrasal. An example of an early interphrasal verbal agreement violation follows: ‘Chaque semaine la voisine remplissent le frigo après avoir fait les courses au marché’ (Every week the neighbour fill the fridge after shopping at the market). The main developmental results were the following: not surprisingly, children were always slower than adults in the detection of grammatical violations. At each age level, morphological violations were more rapidly detected than word order violations. Each age group was faster at judging sentences with later occurring violations and the position effect was especially strong in the youngest groups. Finally, intraphrasal violations were more rapidly detected than interphrasal ones, this effect being observed only in the oldest groups (i.e. 10;10 years and adults). The results were compared to previous on-line data obtained in modern Greek (Kail & Diakogiorgi, 1998) showing strong similarities, even though Greek is a very rich morphological language. These results are discussed within the framework of the Competition Model, outlining the necessity to incorporate new processing constraints into the model.