This is the first study to report how children's language skills and mothers' book-reading strategies, measured at 2;0, predict mastery of word inflections at 3;0 and 5;0 in a sample of 66 Finnish children. Three theoretical models were tested on the longitudinal data using path analyses. The testing of the models suggests direct developmental continuity from producing words and multiword utterances on later inflectional growth, but indirect effects of maternal strategies on language outcomes. Moreover, mothers' complex expansions and questions are positively related, whereas labellings and corrections are negatively related, to children's concurrent and subsequent language skills. Finally, vocabulary size relates negatively to maternal attention regulation. When joint attention is easily built up in the dyad, mothers concentrate more on direct reading, which, together with the child's vocabulary, predicts mastery of inflections. In conclusion, the results can be viewed as support for a child-driven view on the future course of language acquisition.

As Peters (2001) has suggested, the young child's use of fillers seems to indicate awareness of distributionally-defined slots in which some as yet unidentified material belongs. One may view a filler as an emergent transitional form; as a slot that serves as an underspecified lexical entry for the accumulation of phonological and functional information; or as prosodic ‘sentence padding’. We trace the development of three fillers in one English-acquiring child through seven months, from their first appearance about 1;9 through their re-analysis as English functors about age 2;4. We show how the description of these fillers requires an elaboration of the current framework for describing the emergence of morphology, from a one-dimensional to a multi-dimensional model. Finally, we argue that the neglect of such transitional and under-defined elements gives a false picture of development, making it appear as if language development takes place in discontinuous steps.

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.

Rosemarie Tracy is leaving the Editorial Team. I would like to thank her sincerely for the hard work and care that she has put into her work as Associate Editor over the last three years and to welcome Clifton Pye of the University of Kansas and Paul Fletcher of the University of Hong Kong as new Associate Editors.

Final Syllable Lengthening (FSL) has been extensively examined in infant vocalizations in order to determine whether its basis is biological or learned. Findings suggest there may be a U-shaped developmental trajectory for FSL. The present study sought to verify this pattern and to determine whether vocal maturity and deafness influence FSL. Eight normally hearing infants, aged 0;3 to 1;0, and eight deaf infants, aged 0;8 to 4;0, were examined at three levels of prelinguistic vocal development: precanonical, canonical, and postcanonical. FSL was found at all three levels suggesting a biological basis for this phenomenon. Individual variability was, however, considerable. Reduction in the magnitude of FSL across the three sessions provided some support for a downward trend for FSL in infancy. Findings further indicated that auditory deprivation can significantly affect temporal aspects of infant speech production.

Children with specific language impairment (SLI) have well-documented problems in the use of tense-related grammatical morphemes. However, in English, tense often overlaps with aspect and modality. In this study, 15 children with SLI (mean age 5;2) and two groups of 15 typically developing children (mean ages 3;6 and 5;3) were compared in terms of their use of previously studied morphemes in contexts that more clearly assessed the role of aspect. The children's use of less frequently studied morphemes tied to modality or tense was also examined. The children with SLI were found to use -ing to mark progressive aspect in past as well as present contexts, even though they were relatively poor in using the tense morphemes (auxiliary was, were) that should accompany the progressive inflection. These children were inconsistent in their use of third person singular -s to describe habitual actions that were not occurring during the time of their utterance. However, the pattern of the children's use suggested that the source of the problem was the formal tense feature of the inflection, not the habitual action context. The children's use of modal can was comparable to that of the typically developing children, raising the possibility that the modality function of possibility had been learned without necessarily acquiring the tense feature of this morpheme. These children's proficiency with can suggests that their bare verb stem productions should probably not be re-interpreted as cases of missing modals. Together these findings suggest that the more serious tense-related problems seen in English-speaking children with SLI co-occur with a less impaired ability to express temporal relations through aspect and modality.

The present study examined gender and age patterns of diminutive use in conversations between 32 Spanish-speaking Peruvian mothers and their three- and five-year-old children. Results confirm previous findings concerning both parents' greater use of diminutives with younger children and children's early acquisition of this complex aspect of morphology. However, findings do not support previous studies on gender differences in parental use of diminutives with young children. Results also revealed that mothers' and children's imitations of their interlocutors' diminutized words promoted their interlocutors' overall diminutive use. This finding highlights the acute sensitivity of both speakers to each others' language and the potential role of imitation in older children's language development.

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.

Evidence from experimental studies of Spanish children's production of determiners reveals that they pay more attention to phonological cues present in nouns than to natural semantics when assigning gender to determiners (Pérez-Pereira, 1991). This experimental work also demonstrated that Spanish children are more likely to produce the correct determiner when given a noun with phonological cues which suggest it is masculine, and more likely to assign masculine gender to nouns with ambiguous cues. In this paper, we investigate the phonological cues available to children and seek to explore the possibility that differential frequency in the linguistic input explains the priority given to masculine forms when children are faced with ambiguous novel items. A connectionist model of determiner production was incrementally trained on a lexicon of determiner–noun phrases taken from parental speech in a longitudinal study of a child between the ages of 1;7 and 2;11 (López Ornat, Fernandez, Gallo & Mariscal, 1994) preserving the type and token frequency information. An analysis of the database of parental productions revealed that while regular feminine nouns were slightly more frequent than regular masculine nouns, irregular masculine nouns outnumbered irregular feminine nouns by roughly 2 to 1. On the basis of this, we made the prediction that as the training lexicon builds up, the network will perform better overall on masculine determiners than would be predicted from their forms alone and will tend to assign masculine gender to ambiguous novel nouns in a test set. The findings indicate that, at least in the case of Spanish gender agreement for determiners and nouns, a general associative learning mechanism can account for important characteristics of the acquisition process seen in children.

In a first study, we considered whether modelling and the type of an adult's request influenced children's ability at 1;8 and 2;2 to comprehend gestures and replica objects as symbols for familiar objects. In a second study, we evaluated whether modelling and type of request influenced children's ability at 1;8 (N=24) to understand unfamiliar (i.e. unconventional) objects as symbols. Results of Study 1 indicated that children at 2;2 comprehended a gesture as a symbol in the absence of any previous model demonstration. All children comprehended a replica as standing for another object, although modelling marginally improved children's performance at 2;2 and decreased performance at 1;8. In general, the type of request did not influence children's comprehension of gestures or replicas as symbols. Results of Study 2 showed that modelling and request type did not influence children's understanding of objects that are unconventional and novel, as symbols. The studies converge to suggest that symbolic comprehension is a highly context-dependent ability that continues to develop over the second year.

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).

Theorists of language acquisition have long debated the means by which children learn the argument structure of verbs (e.g. Bowerman, 1974, 1990; Pinker, 1984, 1989; Tomasello, 1992). Central to this controversy has been the possible role of verb semantics, especially in learning which verbs undergo dative-shift alternation in languages like English. The learning problem is somewhat simplified in Bantu double object constructions, where all applicative verbs show the same order of postverbal objects. However, Bantu languages differ as to what that order is, some placing the benefactive argument first, and others placing the animate argument first. Learning the language-specific word-order restrictions on Bantu double object applicative constructions is therefore more akin to setting a parameter (cf. Hyams, 1986). This study examined 100 three- to eight-year-old children's knowledge of word order restrictions in Sesotho double object applicatives. Performance on forced choice elicited production tasks found that four-year-olds showed evidence of rule learning, although eight-year-olds had not yet attained adult levels of performance. Further investigation found lexical construction effects for three-year-olds. These findings suggest that learning the argument structure of verbs, even when lexical semantics is not involved, may be more sensitive to lexical construction effects than previously thought.

This paper explores ‘fast mapping’, one of several processes that have been proposed to be involved in the rapid vocabulary expansion observed in the preschool years. An adaptation of a receptive word matching task examined how well children retained a just-mapped relation between word and referent when some information was later missing. Thirty-nine children between the ages of 3;0 and 5;6 (mean age 4;3) were taught to select a black square if the correct match for a spoken label was not visible in an array of pictures presented on a computer screen. This procedure allowed children to respond even when they perceived that the correct referent was absent. In experimental sessions, children experienced a single exposure to a word-referent relation. Then, under one condition they heard the just-learned label but were not presented with the matching referent; instead, a completely novel referent was visible along with the black square. Under another condition, they were presented with a just-learned referent (and the black square) but heard a completely new label. The question of interest was whether the children appreciated that an earlier-learned map precluded re-assigning a label to a new referent or re-assigning a referent with a second new label. If so, they should select the black square under both conditions. The majority of children (69%) resisted re-assigning a just-mapped label to a completely novel referent and selected the black square, even when the original referent was not in sight. However, fewer of these children resisted accepting a second label for a just-named referent (46%). Older children were significantly more likely to adhere to original maps than were younger children.

The aim of the current study was to determine the degree to which a sample of one child's creative utterances related to utterances that the child previously produced. The utterances to be accounted for were all of the intelligible, multi-word utterances produced by the child in a single hour of interaction with her mother early in her third year of life (at age 2;1.11). We used a high-density database consisting of 5 hours of recordings per week together with a maternal diary for the previous 6 weeks. Of the 295 multi-word utterances on tape, 37% were ‘novel’ in the sense that they had not been said in their entirety before. Using a morpheme-matching method, we identified the way(s) in which each novel utterance differed from its closest match in the preceding corpus. In 74% of the cases we required only one operation to match the previous utterance and the great majority of these consisted of the substitution of a word (usually a noun) into a previous utterance or schema. Almost all the other single-operation utterances involved adding a word onto the beginning or end of a previous utterance. 26% of the novel, multi-word utterances required more than one operation to match the closest previous utterance, although many of these only involved a combination of the two operations seen for the single-operation utterances. Some others were, however, more complex to match. The results suggest that the relatively high degree of creativity in early English child language could be at least partially based upon entrenched schemas and a small number of simple operations to modify them. We discuss the implications of these results for the interplay in language production between strings registered in memory and categorial knowledge.

Two studies investigated whether four-year-old children (12 in Experiment 1 with a mean age of 4;8 and 36 in Experiment 2 with a mean age of 4;7) invent names for new artifacts based on the objects' functions as opposed to their perceptual properties. Children informed about the intended functions of novel objects provided more name innovations that were clearly function-based than perception-based. This tendency was observed when children were shown the objects' functions, even if they were also given verbal descriptions of the objects' perceptual properties and parts. Only when ignorant of the objects' intended functions did children tend to use perceptual features to create substantial numbers of names. Accordingly, results from this name-innovation methodology converge with findings from some recent studies of lexical categorization suggesting that functional information is critical to how preschoolers extend artifact names. Children appear to appreciate an intimate relation between the functions of artifacts and how they are named.

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.

This study investigated whether crosslinguistic interference occurs in the domain of subject realization in Spanish in a bilingual acquisition context. We were also interested in exploring whether the source of the interference is due to child-internal crosslanguage contact between English and Spanish, as is commonly assumed, or due to the nature of the language input in a bilingual family, a factor which has not typically been considered in studies of crosslinguistic influence. The use of subjects in a null subject language like Spanish is a phenomenon linked to the pragmatics/syntax interface of the grammar, and thus, is a domain where crosslinguistic interference is predicted to be likely to occur in bilingual acquisition (Müller & Hulk, 2001). Using spontaneous language data available from CHILDES (www.childes.psy.cmu.edu), we examined the use of overt subjects in Spanish by two Spanish monolingual children (ages: 1;8–2;7 and 1;8–1;11) one Spanish–English bilingual child (age 1;9–2;6) and their parental interlocutors. We looked at the proportions of overt versus null subjects as well as the discourse-pragmatic contexts of overt subject use by the children in order to uncover bilingual/monolingual differences in the distributional properties and the functional determinants of subject realization. We also looked at identical variables in the speech of the children's parental interlocutors to investigate the potential influence of the input on the children's output. Our results suggest that the bilingual child showed patterns in her subject realizations in Spanish that could be interpreted as due to crosslinguistic effects from English; however, there is also evidence that these effects may have a source in the input, rather than resulting from internal crosslanguage contact. While our data do not permit us to distinguish conclusively between these two possible sources, they indicate that future research on crosslinguistic influence in bilingual acquisition should take input into account.

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.

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.

Children learning English often omit grammatical words and morphemes, but there is still much debate over exactly why and in what contexts they do so. This study investigates the acquisition of three elements which instantiate the grammatical category of ‘inflection’ – copula be, auxiliary be and 3sg present agreement – in longitudinal transcripts from five children, whose ages range from 1;6 to 3;5 in the corpora examined. The aim is to determine whether inflection emerges as a unitary category, as predicted by some recent generative accounts, or whether it develops in a more piecemeal fashion, consistent with constructivist accounts. It is found that for each child the relative pace of development of the three morphemes studied varies significantly, suggesting that these morphemes do not depend on a unitary underlying category. Furthermore, early on, be is often used primarily with particular closed-class subjects, suggesting that forms such as he's and that's are learned as lexically specific constructions. These findings are argued to support the idea that children learn ‘inflection’ (and by hypothesis, other functional categories) not by filling in pre-specified slots in an innate structure, but by learning some specific constructions involving particular lexical items, before going on to gradually abstract more general construction types.