While it has not been my policy to carry obituaries in the Journal, I would like to note, with deep sorrow, the tragically early death of Peter Jusczyk and to celebrate his major contributions to our field.

I am pleased to announce that the Journal is moving to four issues per year which I hope will help us to publish accepted articles somewhat faster.

I would like to welcome Edith Bavin of La Trobe University as a new Associate Editor. In addition we are also appointing a Statistics Consultant, Glyn Collis, of Warwick University, to assist the action editors when necessary.

We are continuing to publish at least one major Review and Commentary section a year. The next will appear in Issue 2 of this year and will consist of a review article by Dorit Ravid and Liliana Tolchinsky entitled: ‘Developing linguistic literacy: a comprehensive model’ together with a number of commentaries.

Finally, while we prefer not to include formal thanks for our editorial work in the acknowledgement sections of papers unless our contribution has been scientific and/or intellectual, but we are highly appreciative of feedback in correspondence with authors and reviewers.

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.

Attempts to measure phonological acquisition have largely focused on segments, with less effort made to examine whole-word productions. This article proposes four measures designed to estimate a child's whole-word abilities: 1. the PHONOLOGICAL MEAN LENGTH OF UTTERANCE, a measure of whole-word complexity for both child and target words, 2. the PROPORTION OF WHOLE-WORD PROXIMITY, a measure of the proximity between the child's word and its target form, 3. the PROPORTION OF WHOLE-WORD CORRECTNESS, a measure of the number of words produced correctly relative to the sample size, and 4. the PROPORTION OF WHOLE-WORD VARIABILITY, a measure of how often a child produces words in distinct phonological shapes. The central measure is the Phonological Mean Length of Utterance, which can be used to identify a child's stage of acquisition, to assess proximity to target words, and to evaluate the complexity of words. The value of the new measures will be demonstrated through preliminary applications to a range of contexts; i.e. monolingual children acquiring English (five children, 0;11 to 1;5), Cantonese (one child, 1;7), and Spanish (5 children, 2;2 to 2;11), bilingual children acquiring Hungarian-English (one child, 2;0) and Spanish-English (3 children, 2;4 to 2;11), children with phonological impairment (eighteen children, 2;11 to 5;3), and children with cochlear implants (six children, 4;5 to 7;11).

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.

Previous evidence suggests that the structure of similarity neighbourhoods in the developing mental lexicon may differ from that of the fully developed lexicon. The similarity relationships used to organize words into neighbourhoods was investigated in 20 pre-school children (age 3;7 to 5;11) using a two alternative forced-choice classification task. Children classified the similarity of test words relative to a standard word to determine neighbourhood membership. The similarity relationship between the test and standard words varied orthogonally in terms of type of similarity and position of overlap. Standard words were drawn from neighbourhoods differing in density. Results showed that dense neighbourhoods were organized by phoneme similarity in the onset+nucleus or rhyme positions of overlap. In contrast, sparse neighbourhoods appeared to be organized by phoneme similarity in the onset+nucleus, but manner similarity in the rhyme. These results are integrated with previous findings from infants and adults to propose a developmental course of change in the mental lexicon.

This paper focuses on aspects of early lexical acquisition in German. There have been conflicting results in the literature concerning both the pattern of vocabulary growth and the composition of the early lexicon. Our study describes the development of various categories of words and questions the preponderance of nouns in spontaneous speech. 32 children were studied longitudinally through recordings made at age 1;1, 1;3, 1;9 and 3;0. The following properties of the data were investigated: vocabulary size in relation to age, frequency of word use, and distribution of word categories. The results show that use of both types and tokens increases with time. A trend analysis indicates an exponential increase in vocabulary production in the second year, followed by a further expansion. This vocabulary spurt-like pattern can be observed in the use of word types and tokens. The findings in regard to vocabulary composition illustrate the dynamics present in the development of word categories. In the beginning, children use mostly relational words, personal-social words and some onomatopoeic terms. These categories are gradually complemented with nouns, verbs, function words and other words so that we see a balanced lexicon by 3;0. Trend analyses clarify characteristic developmental patterns in regard to certain word categories. Our spontaneous speech data does not support a strong noun-bias hypothesis.

Specific relationships between verbal and nonverbal aspects of caregiver attention-focusing events and later verbal IQ were investigated for a risk sample of 26 very low birthweight [VLBW], preterm [PT] children. Videotaped interactions between VLBW, PT children at 2;0 and their caregivers were coded for caregiver attention-focusing speech and/or caregiver attention-focusing gestures (display, demonstration and pointing), caregiver gesture–speech combinations, and for child attention-sharing through gesture and social gaze. To investigate the specific effects of caregiver and child interactional factors, analyses statistically controlled for cognitive status. Simultaneous multiple regression analyses found that overall caregiver attention-focusing involving gesture, child attention-sharing behaviours, and cognitive status each significantly and uniquely contributed to verbal IQ at 3;0. Further analyses contrasted the contributions of caregiver gesture with relevant descriptive speech, caregiver gesture with no speech/nondescriptive speech, and caregiver pointing. Results of these analyses suggest that caregiver gesture with relevant descriptive speech makes a unique and positive contribution to later language performance.

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.

The effects of maternal interactive styles on the production of referential communication were assessed in four groups of infants whose chronological ages ranged between 0;6 and 1;8. Two groups of infants with Down syndrome (DS), one (n = 11) with a mean mental age (MA) of 0;8.6, and the other (n = 11) of 1;4.5, were matched on MA with two groups (n = 10 each) of typically developing infants. Infants were seen bi-monthly, for 8 months, with mothers, same-aged peers, and mothers of the peers. Results showed that High MA non-Down syndrome (ND) infants produced more words, and High MA DS infants produced more gestures when playing with mothers than peers. Mothers exhibited more attentional maintaining behaviours than peers, in particular to High MA infants, but they redirected the attentional focus of Low MA infants more. Sequential loglinear analyses revealed interesting contingencies between the interactive strategies of mothers and the referential communicative behaviours of their infants. Whereas maintaining attention increased, redirecting attention decreased the likelihood of the production of gestures and words in children. However, redirecting attention was followed by maintaining attention. Thus, mothers redirect the attentional focus in order to promote joint attention and referential communication. Furthermore, words and gestures of the children also promote joint attention in mothers. This highlights the reciprocal nature of these dynamic communicative interactions.

Most children aged 1;6 to 2;0 begin to use utterances of two words or more. It is therefore important for child phonologists to consider the development of phonetic and phonological phenomena that characterize connected speech. The longitudinal case study reported here investigated three juncture types – assimilation, elision and liaison – in the speech of a typically-developing child between the ages of 2;4 and 3;4. Attempts at production of these adult juncture types occurred from the onset of two-word utterances. However, for some juncture types, the child still had to perfect the intergestural relationships and gestural articulations that the adult between-word junctures demand. This process of phonetic development was largely accomplished by the age of 3;4. With one exception, between-word junctures appear not to be the result of learned phonological rules or processes. The exception is liaison involving /r/, which did not occur until the child was three years old.

Children's acquisition of the transitivity status of novel verbs was examined to test whether preemption helps children learn to avoid non-conventional uses of verbs. Given that many English verbs alternate between transitive and intransitive usage (e.g. break, roll), how do children learn the fixed transitive status of verbs such as hit or the fixed intransitive status of verbs such as fall? 48 four-year-olds and 48 six- and seven-year-olds learned two novel verbs, with one verb modelled as transitive and the other as intransitive. Exposure conditions varied the occurrence and type of preemptive evidence potentially facilitating learning of the verbs' transitivity status. In comparison to a No Preemption group, only six- to seven-year-olds exposed to novel verbs in alternative constructions (that allowed them to talk about the actions from the perspective of the agent or patient without changing the verbs' assigned transitivity) produced fewer utterances violating the verbs' fixed transitivity. The results identify limits in children's usage of indirect negative evidence in acquiring verb argument structure constructions.

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 study the ability of children to provide an appropriate continuation for a stimulus sentence, taking into account the joint demands of situational aspect and grammatical aspect. We hypothesize that the aspectual transitions required by some aspectual combinations play a role in the difficulty of providing an appropriate continuation for them. We tested 130 French-speaking children of 5;06 to 9;0. In general, the data are consistent with the idea that the ability of children to construe an appropriate continuation for a stimulus clause is a function of both the situational aspect of the clause and the grammatical aspect provided by the verbal morpheme. There is a significant tense×situational aspect interaction in the number of continuations that children are able to provide in answer to the stimuli. Contrary to our expectations, there is no significant tense×situational aspect in the number of appropriate continuations, this being perhaps due to the small number of continuations for each stimulus type, but there are trends in the expected direction, which further studies may be able to confirm.

Two experiments investigated the factors that govern children's use of singular and plural forms of count nouns. Experiment 1 used an elicited production task to investigate whether children use referential and/or syntactic information to determine the form of the count nouns when the two sources of information conflict (e.g. each x, one of the xs), as well as when the linguistic context does not provide any constraint on the form of the noun, but the referential context does (e.g. the dog(s)). 48 children, aged 1;9 to 5;6, participated in Experiment 1. The results suggest that even the youngest children can use referential information when relevant, and can ignore referential information when necessary. Children did, however, show a tendency to make errors with the quantifier each in non-partitive contexts, and a developmental trend was found in the use and avoidance of each in non-partitive contexts. Experiment 2, an act out task, provided a second test of the role of referential information in children's use of singular and plural forms. Experiment 2 also investigated children's appreciation of the semantic distinction between each and all. 48 children, aged 1;8 to 5;6, participated in Experiment 2. A weak sensitivity to the semantic distinction between the two quantifiers as well as the syntactic context in which they were used was found. The results of the two experiments suggest that, from the beginning, children approach the task of learning when to use singular and plural forms of count nouns on the basis of morpho-syntactic, semantic, and referential properties of utterances, rather than initially using only one of these types of information.

This study investigated different accounts of early argument structure acquisition and verb paradigm building through the detailed examination of the acquisition of the verb Go. Data from 11 children followed longitudinally between the ages of 2;0 and 3;0 were examined. Children's uses of the different forms of Go were compared with respect to syntactic structure and the semantics encoded. The data are compatible with the suggestion that the children were not operating with a single verb representation that differentiated between different forms of Go but rather that their knowledge of the relationship between the different forms of Go varied depending on the structure produced and the meaning encoded. However, a good predictor of the children's use of different forms of Go in particular structures and to express particular meanings was the frequency of use of those structures and meanings with particular forms of Go in the input. The implications of these findings for theories of syntactic category formation and abstract rule-based descriptions of grammar are discussed.

Many recent generativist models attribute grammatical knowledge to young children on the basis that children's language patterns the same way as the target adult language. It has been proposed that the child acquires this knowledge early on in development by a process of parameter setting. Wexler (1996) presents the VERY EARLY PARAMETER SETTING HYPOTHESIS (VEPS), which suggests that basic language-specific parameters are set correctly at the earliest observable stages, that is, from the onset of multi-word speech. However, the patterns predicted by VEPS are necessarily a characteristic feature of the input language and could therefore be just as readily explained in more limited scope terms. A good example of this is French negation where, in order to perform correctly, the child simply has to register that certain lexical forms precede the negative particle pas and certain other forms follow it. One implication of such a limited scope account is that there should be a strong relation between the lexical specificity of children's and mothers' use of verbs before and after pas. We present data for one subject, aged from 2;1 to 2;8, that are compatible with this hypothesis. While these data do not count directly against VEPS, they do suggest that the very low frequency of errors in children's use of French negation does not in and of itself constitute evidence for early syntactic knowledge.

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.

Data from one English-Italian bilingual child (1;10–3;1) are presented in this study which challenge the hypothesis that the consistent realization of overt subjects in English is caused by the emergence of finite verbal morphology in the child's grammar. The argument is made for the emergence of subjects as an independent grammatical property of English, namely the marking of person deixis. Throughout the period of observation there is a significant proportion of overt subjects in the child's English utterances appearing both with finite and non-finite verb forms. Production of subjects stabilizes at 90% of obligatory contexts when no morphological correlates of finiteness have been acquired yet. While subjects are produced at significantly lower rates in Italian, we observe the consolidation of a number of inflected forms marking person agreement. The emergence of overt subjects in English on the one hand, and of subject–verb agreement in Italian on the other suggest that this bilingual child is grammaticalizing the all-important function of person deixis in language-specific ways: the same function is expressed by different forms in the child's two languages.

This paper examines two- to five-year-old children's knowledge of inversion in English yes/no questions through a new experimental study. It challenges the view that the syntax for inversion develops slowly in child English and tests the hypothesis that grammatical competence for inversion is present from the earliest testable ages of the child's sentence production. The experimental design is based on the premise that a valid test of this hypothesis must dissociate from inversion various language-specific aspects of English grammar, including its inflectional system. An elicited imitation method was used to test parallel, lexically-matched declarative and question structures across several different verb types in a design which dissociated subject-auxiliary inversion from the English-specific realization of the inflectional/auxiliary system. Using this design, the results showed no significant difference in amount or type of children's errors between declarative (non-inverted) and question (inverted) sentences with modals or auxiliary be, but a significant difference for sentences with main verbs (requiring reconstruction of inflection through do-support) and copula be. The results from sentences with auxiliary be and those with modals indicate that knowledge of inversion is present throughout our very young sample and does not develop during this time. We argue that these results indicate that the grammar of inversion is present from the youngest ages tested. Our results also provide evidence of development relevant to the English-specific inflectional system. We conclude with a new developmental hypothesis: development in question formation occurs in integrating language-specific knowledge related to inflection with the principles of Universal Grammar which allow grammatical inversion.