When children reduce onset clusters to singletons, a common pattern is for the least sonorous member of the adult cluster to be produced. Within OPTIMALITY THEORY (Prince & Smolensky, 1993), this pattern has been accounted for in terms of a fixed ranking of onset constraints that evaluate a segment's degree of sonority, whereby onset glides violate the highest ranked constraint, and onset stops the lowest. Not all children follow the sonority pattern, however. In this paper, we apply two fundamental principles of optimality theory to yield predictions about other children's cluster reduction patterns. The first principle is that of FACTORIAL TYPOLOGY, according to which all rankings of constraints should yield possible languages. To produce the sonority pattern, all conflicting constraints must rank beneath the onset sonority constraints. If they rank above the onset sonority constraints, these other constraints will force deviations from the sonority pattern. In this paper, we show how divergences from the sonority pattern are caused by three well-motivated conflicting constraints: *FRICATIVE, *DORSAL, and MAX-LABIAL. This is documented in the speech of two normally developing children (about 1;6–2;3) and a child with a phonological delay (3;8). The second principle we appeal to is that of EMERGENT CONSTRAINT ACTIVITY, according to which the effects of violated constraints can be observed when higher ranked conflicting constraints are not at issue. We show that even when the onset sonority constraints are outranked by the conflicting constraints, under the right circumstances the sonority pattern does emerge in the forms produced by these children.

Studies of vowel length acquisition indicate an initial stage in which phonological vowel length is random followed by a stage in which either long vowels (without codas) or short vowels and codas are produced. To determine whether this sequence of acquisition applies to a group of German-speaking children (three children aged 1;3–2;6), monosyllabic and disyllabic words were transcribed and acoustically analysed. The results did not support a stage in which vowel length was totally random. At the first time period (onset of word production to 1;7), one child's monosyllabic productions were governed by a bipositional constraint such that either long vowels, or short vowels and codas were produced. At the second (1;10 to 2;0) and third time periods (2;3 to 2;6), all three children produced target long vowels significantly longer than target short vowels. Transcription results indicated that children experienced more difficulty producing target long than short vowels. In the discussion, the findings are interpreted in terms of the representation of vowel length in children's grammars.

A longitudinal study of one child aged 2;5 documents an invented language game consisting of suffixal reduplication and onset replacement. Initially, reduplication is partial: the reduplicant enlarges in discrete increments over the five stages of the game until by the last stage reduplication is total. Reduplication is accompanied by a process of onset replacement, in which the reduplicant always begins with /b/. Early in the game, this replacive onset ‘dissimilates’ to /p/ whenever the reduplicant would independently have begun with /b/. In subsequent stages, other voiced obstruents trigger dissimilation as well. Though similar in many ways to adult language reduplication, it is argued that J's game may more closely resemble adult rhyme (both poetic and word rhyme). Regardless, the structure of the game clearly reveals the child's awareness, in the third year of life, of stress and metrical feet, segmental natural classes, and segments themselves (phonemic awareness).

This study examined (a) developmental stability and change in children's private speech during the preschool years, (b) across-task consistency in children's self-speech, and (c) across-setting relations between children's private speech in the laboratory and their behaviour at home and in the preschool classroom. A group of 32 normally developing three- and four-year-old children was observed twice (six month inter-observation interval) while engaging in the same individual problem-solving tasks. Measures of private speech were collected from transcribed videotapes. Naturalistic observations of children's behaviour in the preschool classroom were conducted, and teachers and parents reported on children's behaviour at home and school. Individual differences in preschool children's private speech use were generally stable across tasks and time and related to children's observed and reported behaviour at school and home. Children whose private speech was more partially internalized had fewer externalizing behaviour problems and better social skills as reported by parents and teachers. Children whose private speech was largely task-irrelevant engaged in less goal-directed behaviour in the classroom, expressed more negative affect in the classroom, and rated as having poorer social skills and more behaviour problems. Developmental change occurred during the preschool years in children's use and internalization of private speech during problem-solving in the form of a reduction over time in the total number of social speech utterances, a decrease in the average number of words per utterance, and an increase in the proportion of private speech that was partially internalized.

Accounts that specify semantic and/or syntactic complexity as the primary determinant of the order in which children acquire particular words or grammatical constructions have been highly influential in the literature on question acquisition. One explanation of wh-question acquisition in particular suggests that the order in which English speaking children acquire wh-questions is determined by two interlocking linguistic factors; the syntactic function of the wh-word that heads the question and the semantic generality (or ‘lightness’) of the main verb (Bloom, Merkin & Wootten, 1982; Bloom, 1991). Another more recent view, however, is that acquisition is influenced by the relative frequency with which children hear particular wh-words and verbs in their input (e.g. Rowland & Pine, 2000). In the present study over 300 hours of naturalistic data from twelve two- to three-year-old children and their mothers were analysed in order to assess the relative contribution of complexity and input frequency to wh-question acquisition. The analyses revealed, first, that the acquisition order of wh-questions could be predicted successfully from the frequency with which particular wh-words and verbs occurred in the children's input and, second, that syntactic and semantic complexity did not reliably predict acquisition once input frequency was taken into account. These results suggest that the relationship between acquisition and complexity may be a by-product of the high correlation between complexity and the frequency with which mothers use particular wh-words and verbs. We interpret the results in terms of a constructivist view of language acquisition.

Parents frequently check up on what their children mean. They often do this by reformulating with a side sequence or an embedded correction what they think their children said. These reformulations effectively provide children with the conventional form for that meaning. Since the child's utterance and the adult reformulation differ while the intended meanings are the same, children infer that adults are offering a correction. In this way, reformulations identify the locus of any error, and hence the error itself. Analyses of longitudinal data from five children between 2;0 and 4;0 (three acquiring English and two acquiring French) show that (a) adults reformulate their children's erroneous utterances and do so significantly more often than they replay or repeat error-free utterances; (b) their rates of reformulation are similar across error-types (phonological, morphological, lexical, and syntactic) in both languages; (c) they reformulate significantly more often to younger children, who make more errors. Evidence that children attend to reformulations comes from four measures: (a) their explicit repeats of corrected elements in their next turn; (b) their acknowledgements (yeah or uh-huh) as a preface to their next turn; (c) repeats of any new information included in the reformulation; and (d) their explicit rejections of reformulations where the adult has misunderstood. Adult reformulations, then, offer children an important source of information about how to correct errors in the course of acquisition.

Eisenberg (2002) presents data from an experiment investigating three- and four-year-old children's comprehension of restrictive relative clauses (RC). From the results she argues, contrary to Hamburger & Crain (1982), that children do not have discourse knowledge of the felicity conditions of RCs before acquiring the syntax of relativization. This note evaluates this conclusion on the basis of the methodology used, and proposes that an account of syntactic development needs to be sensitive to the real-time processing requirements acquisition places on the learner.

This study investigated young children's ability to use narrative contexts to infer the meanings of novel vocabulary items. Two groups of 15 seven- to eight-year olds participated: children with normally developing reading comprehension skill and children with weak reading comprehension skill. The children read short stories containing a novel word and were required to produce a meaning for the novel word, both before and after its useful defining context. The proximity of the novel word to this context was manipulated. The results supported the hypothesis that children with weak reading comprehension skills are impaired in their ability to integrate information within a text, particularly when that information is non-adjacent and the processing demands are, therefore, high. Analysis of the error data revealed a similar pattern of types of errors for both groups: children with poor reading comprehension were not more likely to produce a thematically inappropriate response than their skilled peers.

Phonological awareness skills are critical for reading acquisition, yet relatively little is known about the origins of phonological awareness. This study investigates one plausible source of the emergence of phonological awareness, phonological neighbourhood density. As vocabulary grows, the number of similar-sounding words in the child's mental lexicon increases. This could create developmental pressure to develop awareness of sub-units within words such as syllables, rhymes and phonemes. If this is the case, then neighbourhood density effects should be discernible in phonological awareness tasks. Children should be more successful in these tasks with words from dense phonological neighbourhoods, as they should show greater awareness of sub-units within these words. We investigated this hypothesis in a group of 48 five-year-old children, most of whom were pre-readers. The five-year-olds with a high vocabulary age showed neighbourhood density effects in a rhyme oddity task, but five-year-olds with lower vocabulary ages did not. This suggests that vocabulary acquisition and consequent neighbourhood density effects are indeed one source of the emergence of phonological awareness skills in pre-readers.

Twenty-four caregivers and their two- to four-year-old children took part in a storybook reading task in which caregivers taught children novel labels (‘DAXY’) for familiar objects. One group (N=12) received labels modelled syntactically as proper names (‘This is NAMED DAXY’), and another group (N=12) received the same labels for the same objects modelled syntactically as adjectives (‘This is VERY DAXY’). Caregivers took strikingly different approaches to teaching words from the two lexical categories. In teaching proper names, but not adjectives, caregivers flagged cases in which one word was paired with two objects; two words were paired with one object; and one word was paired with an inanimate object. In teaching adjectives, but not proper names, caregivers discussed meaning and offered translations. Caregivers' distinctive strategies for teaching proper names and adjectives are congruent with recent findings about children's word meaning assumptions, and with analyses of the semantics of these lexical categories. The findings indicate that parental speech could provide a rich source of information to children in learning how different lexical categories are expressed in their native language.