Verb inflectional morphology and prepositions are loci of difficulty for bilingual children with typical language development (TLD) as well as children with Specific Language Impairment (SLI). This paper examines errors in these linguistic domains in these two populations. Bilingual English–Hebrew and Russian–Hebrew preschool children, aged five to seven, with TLD, and age-matched monolingual Hebrew-speaking children with SLI, were tested using sentence completion and sentence imitation tasks in their L2 Hebrew. Our findings show that, despite the similarity in the locus of errors, the two populations can be distinguished by both the quantity and the quality of errors. While bilingual children with TLD had substitution errors often motivated by the first language, most of the errors of monolingual children with SLI involved omission of the whole morpheme or feature reduction. This difference in the nature of the errors is discussed in terms of bilingual processing vs. impaired representation.

In a conversation, adults expect speakers to be consistent in their use of a particular expression. We examine whether four-year-olds expect speakers to use consistent referential descriptions and whether these expectations are partner-specific. Using an eye-tracking paradigm, we presented four-year-olds with arrays of objects on a screen. During training, Experimenter 1 (E1) used a target expression to identify one object (i.e. “the spotted dog” to identify a dog that is both spotted and fluffy). Following training, either E1 or a new conversational partner (E2) presented children with test trials. Here, the target objects were referred to using either the original expression (e.g. “the spotted dog”) or a new expression (e.g. “the fluffy dog”). Eye-movements indicated that preschoolers were quicker to identify the target referent when the original expression was used by the same speaker. This suggests that four-year-olds, like adults, expect communicative partners to adhere to referential pacts.

This study examines the comprehension and production of subject and object relative clauses (SRCs, ORCs) by children with Specific Language Impairment (SLI) and their typically developing (TD) peers. The purpose is to investigate whether relative clauses are problematic for Danish children with SLI and to compare errors with those produced by TD children. Eighteen children with SLI, eighteen TD age-matched (AM) and nine TD language-matched (LM) Danish-speaking children participated in a comprehension and in a production task. All children performed better on the comprehension compared with the production task, as well as on SRCs compared to ORCs and produced various avoidance strategies. In the ORC context, children with SLI produced more reversal errors than the AM children, who opted for passive ORCs. These results are discussed within current theories of SLI and indicate a deficiency with the assignment of thematic roles rather than with the structural make-up of RCs.

Both off-line and on-line comprehension studies suggest not only toddlers and preschoolers, but also older school-age children have trouble interpreting contrast-marking pitch prominence. To test whether children achieve adult-like proficiency in processing contrast-marking prosody during school years, an eye-tracking experiment examined the effect of accent on referential resolution in six- to eleven-year-old children and adults. In all age groups, a prominent accent facilitated the detection of a target in contrastive discourse sequences (pink cat→green cat), whereas it led to a garden path in non-contrastive sequences (pink rabbit→green monkey: the initial fixations were on rabbits). While the data indicate that children as young as age six immediately interpret contrastive accent, even the oldest child group showed delayed fixations compared to adults. We argue that the children's slower recovery from the garden path reflects the gradual development in cognitive flexibility that matures independently of general oculomotor control.

The objective of this work was to analyze morphosyntactic development in a wide sample of children with Down syndrome (DS) (n = 92) and children with typical development (TD) (n = 92) with a mental age (MA) of 20 to 29 months. Children were individually matched for gender and MA (Analysis 1) and for vocabulary size (Analysis 2). Information about morphosyntax was obtained using an adaptation of the CDI for children with DS. In both analyses, the number of children with DS and with TD who combined words was similar. Analysis 1 showed that children with DS produced shorter utterances, with less morphosyntactic complexity and less morphological suffixes than children with TD, despite having the same mental age. The developmental pattern was similar, although slower in children with DS. Analysis 2 showed that the performance of children with DS was lower than the performance of children with TD in relation to morphosyntactic complexity and morphological suffixes.

The aim of the present study was to examine the contextual effects of social games on prelinguistic vocalizations. The two main goals were to (1) investigate the functions of vocalizations as symptoms of affective arousal and symbols of social understanding, and (2) explore form–function (de)coupling relations between vocalization types and game contexts. Seventy-one six-month-olds and sixty-four twelve-month-olds played with their mothers in normal and perturbed tickle and peek-a-boo games. The effects of infant age, game, game climax, and game perturbation on the frequency and types of infant vocalizations were examined. Results showed twelve-month-olds vocalized more mature canonical syllables during peek-a-boo and more primitive quasi-resonant nuclei during tickle than six-month-olds. Six- and twelve-month-olds increased their vocalizations from the set-up to climax during peek-a-boo, but they did not show such an increase during tickle. Findings support the symptom function of prelinguistic vocalizations reflecting affective arousal and the prevalence of form–function decoupling during the first year of life.

Pronunciation variation is under-studied in infant-directed speech, particularly for consonants. Regressive place assimilation involves a word-final alveolar stop taking the place of articulation of a following word-initial consonant. We investigated pronunciation variation in word-final alveolar stop consonants in storybooks read by forty-eight mothers in adult-directed or infant-directed style to infants aged approximately 0;3, 0;9, 1;1, or 1;8. We focused on phonological environments where regressive place assimilation could occur, i.e., when the stop preceded a word-initial labial or velar consonant. Spectrogram, waveform, and perceptual evidence was used to classify tokens into four pronunciation categories: canonical, assimilated, glottalized, or deleted. Results showed a reliable tendency for canonical variants to occur in infant-directed speech more often than in adult-directed speech. However, the otherwise very similar distributions of variants across addressee and age group suggested that infants largely experience statistical distributions of non-canonical consonantal pronunciation variants that mirror those experienced by adults.

Several models of language acquisition have emerged in recent years that rely on computational algorithms for simulation and evaluation. Computational models are formal and precise, and can thus provide mathematically well-motivated insights into the process of language acquisition. Such models are amenable to robust computational evaluation, using technology that was developed for Information Retrieval and Computational Linguistics. In this article we advocate the use of such technology for the evaluation of formal models of language acquisition. We focus on the Traceback Method, proposed in several recent studies as a model of early language acquisition, explaining some of the phenomena associated with children's ability to generalize previously heard utterances and generate novel ones. We present a rigorous computational evaluation that reveals some flaws in the method, and suggest directions for improving it.

This study focuses on morphophonology and frequency in past tense production. It was assessed whether Dutch five- and seven-year-old typically developing (TD) children and eight-year-old children with specific language impairment (SLI) produce the correct allomorph in regular, irregular, and novel past tense formation. Type frequency of the allomorph, token frequency and phonotactic probability (PP) of the novel verb form are considered. The results showed all groups were sensitive to the phonological cue. PP did not contribute to past tense inflection of novel verbs in any of the groups, but type frequency did in all three groups. Only the seven-year-old typically developing children relied on token frequency for inflection of regulars. The findings point to an important role of phonology and frequency in past tense acquisition for both TD children and children with SLI. We discuss how the SLI performance pattern relates to theories on SLI.

Previous studies have shown that by 11 but not by 10 months infants recognize words that have become familiar from everyday life independently of the experimental setting. This study explored the ability of 10-, 11-, and 12-month-old infants to recognize familiar words in sentential context, without experimental training. The headturn preference procedure was used to contrast passages containing words likely to be familiar to the infants with passages containing words unlikely to have been previously heard. Two stimulus words were inserted near the beginning and end of each of a set of simple sentence frames. The ability to recognize the familiar words within sentences emerged only at 12 months of age. The contrast between segmentation abilities as they emerge as a result of everyday exposure to language, as assessed here, and those abilities as measured in studies in which words are experimentally trained is discussed in terms of memory-based mechanisms.