Two lawful relationships involving word-initial onset clusters have been advanced in the acquisition literature; namely, that clusters imply affricates, and that liquid clusters imply a liquid distinction. This study evaluated and extended the validity of these implicational laws in a population of 110 children (aged 3;0 to 8;6) with functional phonological delays who contributed extended speech samples for computational analyses. Results indicated that, for the most part, the composition of children's sound systems were in compliance with the proposed laws; however, there were noted asymmetries and apparent exceptions in the data. The asymmetries motivated an integration of the two laws to reveal a pattern of segmental–prosodic cyclicity consistent with deterministic models of phonological acquisition. The apparent exceptions highlighted the relevance of independent methodologies and offered a potential theoretical alternative with the Resolvability Principle as directions for future research.

This longitudinal study including 87 infant–mother dyads examined the relation between infant temperamental attention, maternal encouragement of attention, language, and the effects of gender. At ages 0;4, 0;8, and 1;0, global attention was assessed from Rothbart's (1981) IBQ; manipulative exploration was assessed with the Bayley (1969) IBR; and maternal verbal, visual and physical encouragement of attention were coded from 5 minutes of mother–infant free-play. At 1;0, language was measured using language items from the Bayley Mental Scale and parent-report items from Hendrick, Prather & Tobin's (1984) SICD-Revised. Multiple regressions indicated that gender, infants’ manipulative exploration and maternal physical encouragement of attention at 0;4, and maternal verbal encouragement of attention at 1;0, were all positively related to language at 1;0. Interactions indicated that girls high in 0;8 or 1;0 manipulative exploration had more advanced language skills than girls low in manipulative exploration or than boys, regardless of their attention level. Additionally, maternal verbal encouragement of attention appears to be particularly salient in the development of language for boys.

This research investigates language-general and language-specific properties of the acquisition of argument structure. Ten French preschoolers enacted forty sentences containing motion verbs; sixteen sentences were ungrammatical in that the syntactic frame was incompatible with the standard argument structure for the verb (e.g. *Le tigre va le lion = *The tiger goes the lion). Previous work (Naigles, Fowler & Helm; Naigles, Gleitman & Gleitman indicated that English-speaking two-year-olds faced with such ungrammatical sentences consistently altered the usual meaning of the verb to fit the syntactic frame (FRAME COMPLIANCE) whereas adults faced with the same sentences altered the syntax to fit the meaning of the verb (VERB COMPLIANCE). The age at which children began to perform Verb Compliantly varied by frame and by verb. The current study finds that the level of Verb Compliance in French five-year-olds largely mirrors that of English-speaking five-year-olds. The sole exception is the intransitive frame with an added prepositional phrase (e.g. *Le tigre amène près de la passerelle = *The tiger brings next to the ramp), which elicits a higher level of Verb Compliance among French kindergarteners than among their English learning peers. This effect may be due to the unambiguous interpretation of French spatial prepositions (i.e. next to has both locative and directional interpretations whereas près de supports only the locative interpretation). These data support the conclusion that the acquisition of argument structure is influenced by both language-general mechanisms (e.g. uniqueness, entrenchment) and language-specific properties (e.g. prepositional ambiguity).

Two nonce-word studies examined German-speaking children's productivity with the Perfekt (present perfect) from 2;6 to 3;6. The German Perfekt consists of the past participle of the main verb and an inflected form of an auxiliary (either haben ‘have’ or sein ‘be’). In Study 1, nonce verbs were either introduced in the infinitival form, and children (seventy-two children, aged 2;6 to 3;6) were tested on their ability to produce the Perfekt, or introduced in the Perfekt, and children were tested on their ability to produce the infinitive. In Study 2 twenty-four children aged 3;6 were given the past participle form of nonce verbs to see if they could supply the appropriate auxiliary (based mainly on verb semantics). The results were that many children as young as 2;6 used past participles productively (more than used infinitival forms productively), but all children had much difficulty in supplying both auxiliaries appropriately. The current findings suggest that mastery of the Perfekt construction as a whole does not take place before the age of four and that frequency of exposure is an important factor in determining the age at which children acquire grammatical constructions.

We present morphological analyses of verb inflections produced by 15 Spanish-speaking children (age range: 1;7 to 4;7) taken from longitudinal and cross-sectional samples of spontaneous speech and narratives. Our main observation is the existence of a dissociation between regular and irregular processes in the distribution of errors: regular suffixes and unmarked (non-alternating) stems are over-extended to irregulars in children's inflection errors, but not vice versa. We also found that overregularization errors at all ages are only a small minority of the children's irregular verbs, that the period of overregularization is preceded by a stage without errors, and that the onset of overregularizations is connected to the emergence of obligatory finiteness markings. These findings are explained in terms of the dual-mechanism model of inflection.

Navajo and Quechua, both languages with a highly complex morphology, provide intriguing insights into the acquisition of inflectional systems. The development of the verb in the two languages is especially interesting, since the morphology encodes diverse grammatical notions, with the complex verb often constituting the entire sentence. While the verb complex in Navajo is stem-final, with prefixes appended to the stem in a rigid sequence, Quechua verbs are assembled entirely through suffixation, with some variation in affix ordering.

We explore issues relevant to the acquisition of verb morphology by children learning Navajo and Quechua as their first language. Our study presents naturalistic speech samples produced by five Navajo children, aged 1;1 to 4;7, and by four Quechua-speaking children, aged 2;0 to 3;5. We centre our analysis on the role of phonological criteria in segmentation of verb stems and affixes, the production of amalgams, the problem of homophony, and the significance of distributional learning and semantic criteria in the development of the verb template. The phenomena observed in our data are discussed in light of several proposals, especially those of Peters, Pinker, Slobin, and Hyams.

This study focuses on the mapping of events onto verb-argument structures in British Sign Language (BSL). The development of complex sentences in BSL is described in a group of 30 children, aged 3;2–12;0, using data from comprehension measures and elicited sentence production. The findings support two interpretations: firstly, in the mapping of concepts onto language, children acquiring BSL overgeneralize the use of argument structure related to perspective shifting;secondly, these overgeneralizations are predicted by the typological characteristics of the language and modality. Children under age 6;0, in attempting to produce sentences encoded through a perspective shift, begin by breaking down double-verb constructions (AB verbs) into components, producing only the part of the verb phrase which describes the perspective of the patient. There is also a prolonged period of development of non-manual features, with the full structure not seen in its adult form until after 9;0. The errors in the use of AB verbs and the subsequent protracted development of correct usage are explained in terms of the conceptual–linguistic interface.

Several theorists have proposed that children may interpret an ambiguous word by attending to the dimension that is most relevant in the immediate discourse context. The current study offers a direct test of this hypothesis. Children aged 2;6 and 3;4 (N = 24 in each group) were presented with a novel object with an unusual shape and texture and were told ‘This is a dacky one’. In the Shape-Relevant condition, two other objects' shapes were described before the target object was labelled (‘This is a round one; this is a square one’). In the Texture-Relevant condition, two preceding objects' textures were described (‘This is a smooth one; this is a fuzzy one’). Subsequent comprehension tests indicated that, in extending the novel adjective to other exemplars, children attended to the dimension that was most relevant to the preceding discourse context.

This study compared naturalistic samples of three features of language in 30 two-year-olds – total utterances, word roots, and MLU – in the home in three contrasting situations: the child observed playing by her/himself with mother near by, the child and mother observed in direct play interaction, and the child and mother unobserved at a time the mother judged would provide a sample of the child's ‘optimal’ language. Children produced more utterances and word roots and expressed themselves in longer MLU when in interaction than when playing ‘alone’, but children's utterances, word roots, and MLU were greatest in the ‘optimal’ language production situation. Girls used more word roots and spoke in longer MLU (especially in the ‘optimal’ language situation) than boys. Despite mean level differences, children maintained their rank orders across the three situations in use of word roots and in MLU. These findings have implications for understanding children's language and the representativeness of sampling child language.