Icelandic and Norwegian past tense morphology contain strong patterns of inflection and two weak patterns of inflection. We report the results of an elicitation task that tests Icelandic and Norwegian children's knowledge of the past tense forms of a representative sample of verbs. This cross-sectional study of four-, six- and eight-year-old Icelandic (n=92) and Norwegian (n=96) children systematically manipulates verb characteristics such as type frequency, token frequency and phonological coherence – factors that are generally considered to have an important impact on the acquisition of inflectional morphology in other languages. Our findings confirm that these factors play an important role in the acquisition of Icelandic and Norwegian. In addition, the results indicate that the predominant source of errors in children shifts during the later stages of development from one weak verb class to the other. We conclude that these findings are consistent with the view that exemplar-based learning, whereby patterns of categorization and generalization are driven by similarity to known forms, appropriately characterizes the acquisition of inflectional systems by Icelandic and Norwegian children.

Vocalizations of two female infants, recorded over a 5-week period after the first emergence of cooing, were studied. The vocalizations were classified as cry, discomfort, vegetative and cooing (comfort) sounds. Fifty vocalizations of each sound type, distributed across the 5-week period of study, were selected from the output of each infant (400 vocalizations in all). The features of voicing, breath direction and consonant-like versus vowel-like were documented for each sound type. It was found that the features of the more primitive sound types regrouped themselves in comfort sounds. For the first time the feature of consonant-like was found to co-occur with voicing and egressive (outgoing) breath direction. The implications for theories of pre-speech development are discussed.

The communicative functions of pitch direction and pitch range during the second year were investigated. The research focusses on initial plus repeated requests, either for objects or for co-operation, which were contrasted against giving, showing and labelling. Infants aged 1; 2 to 1;10 were observed in interaction with their mothers in a semistructured situation. Vocalizations were coded separately for communicative function and for prosodic features. Results show that pitch range is consistently higher (1) for repeated requests than for initial requests for objects and (2) for initial requests for objects and for co-operation than for labelling. Giving and showing have an intermediate rank between requests and labelling. Trends in prosodic contours were observed in both requests and labelling: rising tones were more frequently associated with requests whereas falling tones appeared more often in conjunction with labelling.

The acquisition of to in infinitive complement structure was examined in the spontaneous speech data from four children, who were observed longitudinally from two to three years of age. The children learned to as a complementizer connective in the context of a small group of verbs and other matrix forms that take a verb phrase complement. They did not learn to in the context of the complement verbs to mark the infinitive. Secondly, the children learned to with the meaning ‘direction towards’ and not as a meaningless syntactic marker. These results contribute to understanding the relation between the acquisition of complex syntax and the verb system in child language, and to evaluating traditional and contemporary linguistic theories of infinitive complement structure in English.

Counter to findings in English, German and Hebrew, recent acquisition studies have shown that the passive is acquired early in several non-Indo-European languages. In an attempt to explain this phenomenon, this paper addresses certain typological phenomena which influence the early acquisition of passives in Sesotho, a southern Bantu language. After outlining the structure of the Sesotho passive and its syntactic and discourse functions, I examine Sesotho-speaking children's spontaneous use of passives, showing that the acquisition of passives in Sesotho is closely linked to the fact that Sesotho subjects must be discourse topics. I conclude that a detailed examination of how passive constructions interact with other components of a given linguistic system is critical for developing a coherent and universally applicable theory of how passives are acquired.

This study assesses the extent of phonetic continuity between babble and words in four Italian children followed longitudinally from 0 ; 9 or 0 ; 10 to 2 ; 0 – two with relatively rapid and two with slower lexical growth. Prelinguistic phonetic characteristics, including both (a) consistent use of specific consonants and (b) age of onset and extent of consonant variegation in babble, are found to predict rate of lexical advance and to relate to the form of the early words. In addition, each child's lexical profile is analyzed to test the hypothesis of non-linearity in phonological development. All of the children show the expected pattern of phonological advance: Relatively accurate first word production is followed by lexical expansion, characterized by a decrease in accuracy and an increase of similarity between word forms. We interpret such a profile as reflecting the emergence of word templates, a first step in phonological organization.

The ability to extract meaning through the use of syntactic cues, adapted from Naigles' (1990) paradigm, was investigated in Hebrew-speaking children with autism, those with specific language impairment (SLI) and those with typical language development (TLD), in an attempt to shed light on similarities and differences between the two diagnostic categories, both defined by primary language deficits. Thirteen children with autism and 13 with SLI were matched on chronological age, level of language functioning and gender, and 13 children with TLD were matched to the children in the two clinical groups according to language level, as measured by the CELF-P. Children with autism and children with TLD learned novel words using the syntactical cues in the sentences in which they were presented, whereas children with SLI experienced more difficulty, learning only that which would be expected from chance according to the binomial test. Only 4 of the 13 children with SLI (31%) learned the new words, whereas 11 children with autism and 10 children with TLD learned the novel verb using syntactical cues from the sentence frame. The results are analyzed in terms of possible underlying mechanisms in language acquisition. Children with autism seem to rely on relatively intact syntactic abilities, while children with SLI seem to have marked impairment in using this mechanism in acquiring word meaning. Implications for future research and intervention with preschool children with primary language disorders are discussed.

This paper investigates the acquisition of compound vs. phrasal stress (hót dog vs. hot dóg) in English. This has previously been shown to be acquired quite late, in contrast to recent research showing that infants both perceive and prefer rhythmic patterns in their own language. Subjects (40 children in four groups the averages ages of which are 5;4, 7;2, 9;3 and 11;6 and 10 adults) were shown pairs of pictures representing a compound word and the corresponding phrase. They heard a prerecorded tape with the names of the items, and were asked to indicate which one they heard. In addition to 9 real compounds and corresponding phrases, 9 novel compounds were presented (rédcup = invented type of flower vs. red cúp). A gradual increase in overall correct scores until age twelve was found along with a significant effect of real vs. novel compounds (p < 0·001), and an overwhelming tendency for the younger children to prefer compounds regardless of stress. We conclude that the results are due to the slow development of the ability to use prosodic information to override a strong lexical bias.

The contribution of parent input to children's subsequent expressive verb diversity was explored in twenty typically developing toddlers with small verb lexicons. Child developmental factors and parent input measures (i.e. verb quantity, verb diversity, and verb-related structural cues) at age 1;9 were examined as potential predictors of children's verb production in spontaneous language samples at age 2;3. Parent verb input diversity, rather than input quantity, was the primary input factor contributing to children's subsequent verb diversity. Regression analysis showed that verb diversity in parent input at age 1;9 accounted for 30% of the variance in children's verb production six months later, with children's total vocabulary size at age 1;9 accounting for an additional 16% of the variance. These findings demonstrate the relative contributions of developmental and input factors to individual differences in toddlers’ language development and establish the importance of input diversity to verb acquisition.

The comprehension of nine intonational contrasts involving different intonation-groupings, different nucleus placements, and different tones, was examined in 20 ten-year-old children and 20 adults. Fewer ten-year-olds than adults answered correctly on almost all tasks. Initial hypotheses concerning the order of acquisition among the three systems (grouping, nucleus placement, and tone) were in general not confirmed. But the distinction between context-wide and context-limited tonal meanings was predictive of acquisition; and a similar distinction based on local meanings rather than on the intonation patterns themselves is likely to apply to groupings and nucleus placements.

Although children acquire Spanish subjunctive morphology early in the process of language acquisition, they only master mood selection in a staged process that lasts for several years. This paper examines the possibility that the acquisition of subjunctive mood selection in particular syntactic contexts is constrained by cognitive development in the area of representational theory of mind. Acquisition of the epistemic aspects of the semantics of subjunctive are shown to be associated with the understanding of false beliefs, a landmark development in children's cognition. Twenty-two Spanish speaking children between the ages of 3;5 and 6;11 participated in an elicited production study designed to test whether children's ability to produce subjunctive relative clauses was related to their ability to pass a false belief task. Results indicate a strong correlation between children's ability to use the subjunctive mood in relative clauses and their capacity for understanding false beliefs.

Words artificially isolated from twelve parents' speech to their children (aged 1; 10–3; 0) were significantly less intelligible to adult listeners than words originally spoken to an adult. This effect holds for randomly sampled words and, to a lesser extent, for matched pairs. While parents did not adjust the clarity of word tokens to the linguistic naiveté of the child listeners, they did adjust intelligibility inversely to the observed predictability of the sampled words in their sentence contexts, and words to children proved more redundant in this sense. The relationship of these findings to other work on the clarity of motherese is examined and the implications for the study of children's speech perception outlined.

This study examines the relative contributions of rote-memorization, analogic formation and rule-operation in the production of plurals by Hungarian children. In order to maximize analogic formations, each of fifteen actual roots was matched to a rhyming nonsense root. The elicited plural responses were characterized in terms of five stages of morphological learning. The importance of rule-operation as an explanation of word formation was evidenced by the fact that children producing responses characteristic of a given stage did not produce responses for later stages. The contribution of analogic formation was seen to be minimal and the effect of rote-memorization only somewhat greater.

Properties of the input, such as raw frequency and syntactic diversity, have been shown to play a role, to different extents, in the acquisition of nouns and verbs. This study investigated the relationship between three properties of the input (input frequency, syntactic diversity, and variety in noun-type co-occurrence) and age of acquisition of English adjectives. In addition, this study explored the relationship between adjectival semantic typology and order of acquisition. The data are 7262 child utterances and 6318 maternal utterances containing one of 272 adjective in the language samples of two children, Sarah and Adam, from age 2;3 to 5;0 (Brown, 1973) available in CHILDES (MacWhinney, 2000). Statistical analyses revealed that all three properties of the input were significantly correlated with age of acquisition, but variety in noun-type co-occurrence was not a significant predictor once input frequency and syntactic diversity were taken into account. Semantic analyses revealed that the distribution of adjective types and tokens differed between the children and the mothers (to an extent) when the data were examined in terms of adjectival semantic types. The results suggest that both properties of the input and the semantic properties of the English adjective class play a role in its acquisition.

This is a study of the lexical and grammatical abilities of 16 lexically precocious talkers. These children, aged 2;0 were compared to their age-matched peers, 22 typical talkers aged 2;0, and their expressive vocabulary-matched peers, 22 typical talkers aged 2;6. Individual differences in children's lexical knowledge at 2;0 were stable – evident in parent report, laboratory observation, and an experimental fast-mapping paradigm. In accordance with the continuity hypothesis, the lexically precocious children were also grammatically precocious, having a greater representation of grammatical types and tokens and more advanced combinatorial language than their typical age-matches. Their grammatical development was very similar to that of their older vocabulary-matched peers. Limits on continuity were highly constrained with no true dissociation between the lexicon and the grammar in 33 cases examined. We conclude that, among two-year-olds, grammatical development is more tightly associated with the size of the lexicon than with chronological age.

The paper examines the first twenty verb-forms recorded for six Hebrew-speaking children aged between 1;2 and 2;1, and how they evolve into fully inflected verbs for three of these children. Discussion focuses first on what word-forms children initially select for the verbs they produce, what role these forms play in children's emergent grammar, and how emergent grammar is reflected in the acquisition of fully inflected forms of verbs. Children's early verb repertoire indicates that they possess a strong basis for moving into the expression of a variety of semantic roles and the syntax of a range of different verb–argument structures. On the other hand, children's initial use of verbs demonstrates that they still need to acquire considerable language-particular grammatical knowledge in order to encode such relations explicitly. This language-particular knowledge demonstrates a clear pattern of acquisition, in which aspect precedes inflectional marking for gender, followed by tense, and then by person.

When two people talk about an object, they depend on joint attention, a prerequisite for setting up common ground in a conversational exchange. In this study, we analyze this process for parent and child, with data from 40 dyads, to show how adults initiate joint attention in talking to young children (mean ages 1 ; 6 and 3 ; 0). Adults first get their children's attention with a summons (e.g. Ready?, See this?), but cease using such forms once children give evidence of attending. Children signal their attention by looking at the target object, evidence used by the adults. Only at that point do adults begin to talk about the object. From then on, they use language and gesture to offer information about and maintain attention on the target. The techniques adults rely on are interactive: they establish joint attention and maintain it throughout the exchange.

The early production of nine cohesive devices during narration about personal experience was examined in an 18-month longitudinal study of 10 children between approximately age 2;0 and 3;6. The specification of noun phrases and types of noun errors were also explored. The number of cohesive ties increased with both age and MLU, due to increased pronominal reference and conjunctions (while clausal and verbal ellipsis decreased). Specific cohesive devices also were acquired at different MLU levels. Most noun phrases were non-problematic and errors declined with increasing age and MLU; specifically, noun omissions declined. However, when new nouns were introduced, approximately one out of five were ambiguous throughout the study. Thus, children's narratives become more comprehensible with age as cohesive links increase and noun errors decrease, but at 3;6 children are still having difficulty properly managing the introduction of novel nouns.

The present paper is concerned with establishing the relative difficulty involved in the acquisition of the temporal conjunctions before and after. It tries to control the influence on performance of the following variables: contextual support within a sentence (logically/arbitrarily ordered sequences), order of mention, syntactic complexity, task requirement variables, and memory load. In addition, experiments intended to throw light on the cognitive mechanisms underlying an understanding of these conjuctions are described. The concept of time is supposed to be spatial in origin. An understanding of relative time is dependent on ability to decentre and coordinate. Finally, it is suggested that reversible thinking (in a Piagetian sense) is involved in the process of making inverse sentence order agree with event order.

A speaker's regional dialect is a rich source of information about that person. Two studies examined five- to six-year-old children's perception of regional dialect: Can they perceive differences among dialects? Have they made meaningful social connections to specific dialects? Experiment 1 asked children to categorize speakers into groups based on their accent; Experiment 2 asked them to match speakers to (un)familiar cultural items. Each child was tested with two of the following: the child's Home dialect, a Regional variant of that dialect, and a Second-Language variant. Results showed that children could successfully categorize only with a Home vs. Second-Language dialect contrast, but could reliably link cultural items with either a Home vs. Second-Language or a Regional vs. Second-Language dialect contrast. These results demonstrate five- to six-year-old children's developing perceptual skill with dialect, and suggest that they have a gradient representation of dialect variation.