Global tendencies for the relative absence of covocalization (simul- taneous talk) have been identified in both conversations between adult partners and conversations between mothers and their infants; in each case, the alternating mode in which one partner speaks at a time is predominant. The present investigation examined the timing of the partners' talk in mother-infant engagements over infant age to determine whether: (a) variations occur in the incidence of the alternating mode; and (b) variations occur in the extent to which the alternating mode predominates. Conversations involving a total of 48 mothers and their infants aged from 0;3 to 2;0 were investigated at each of eight infant ages (0;3, 0;6, 0;9, 1;0, 153, 1;6, 1;9 and 2;0). The results indicated that, within a global tendency for the relative absence of covocalization, there was: (a) a curvilinear tendency for the incidence of covocalization to decrease over the first 18 months, and then to increase; and (b) a linear tendency for the extent to which the alternating mode predominates to increase over age. These changes are interpreted as reflecting the facilitative effects of covocalization in the case of young preverbal infants, and the need for the alternating, turn-taking pattern to predominate as mutual comprehension becomes possible in conversations between mothers and their older infants.

Young children typically do not use order-of-mention to resolve ambiguous pronouns, but may do so if given additional cues, such as gestures. Additionally, this ability to utilize gestures may be enhanced in bilingual children, who may be more sensitive to such cues due to their unique language experience. We asked monolingual and bilingual four-year-olds and adults to determine referents of ambiguous pronouns given order-of-mention and co-referential localizing gestures. Results showed that bilingual children, like adults, but not monolingual children, used order-of-mention with gestures to resolve ambiguous pronouns. This highlights a wider implication of bilingualism for socio-cognitive development in children.

Responsive parental communication during an infant's first year has been positively associated with later language outcomes. This study explores responsivity in mother–infant communication by modeling how change in guiding language between 7 and 11 months influences toddler vocabulary development. In a group of 32 mother–child dyads, change in early maternal guiding language positively predicted child language outcomes measured at 18 and 24 months. In contrast, a number of other linguistic variables – including total utterances and non-guiding language – did not correlate with toddler vocabulary development, suggesting a critical role of responsive change in infant-directed communication. We further assessed whether maternal affect during early communication influenced toddler vocabulary outcomes, finding that dominant affect during early mother–infant communications correlated to lower child language outcomes. These findings provide evidence that responsive parenting should not only be assessed longitudinally, but unique contributions of language and affect should also be concurrently considered in future study.

Fifty-two children aged 2; 5 to 6; 3 acted out the meaning of reversible passive and inverted cleft sentences. The younger children overgeneralized two strategies that led to passive sentence reversal. In order of frequency, they are: (1)‘agent + action’ (the noun preceding the verb being interpreted as agent even when it is the second noun), and (2) ‘order-of-mention’ (the first noun being treated as agent). Whereas younger children tended to use an individually consistent approach to both structures, older children were more likely to vary their approaches when they did not comprehend a structure.

The ability to differentiate the directive senses of ask and tell was investigated using a production task in an experimental setting with children between the ages of 2; 6 and 6; 6. Results showed that the children at all ages distinguished the verbs along dimensions sensitive to adult ratings of politeness. There was a trend towards increased politeness with age under ask instructions, but not with tell instructions. Analyses of structural features of the directives produced showed that the interrogative form was more likely to be used with ask instructions, as was the word please, while tell instructions elicited the imperative, with less frequent use of please. The findings suggest that children before the age of 7; 0 are able to differentiate the illocutionary forces of utterances which have the same communicative intention.

H. Clark's hypotheses regarding the acquisition of spatial terms were tested using a task designed to elicit subjects' descriptions of different object arrangements. Children from 3 to 10 years and a group of adults were tested. There was some support for Clark's prediction that the perceptual difficulty of each dimension will affect the order of acquisition of the associated linguistic terms, in that the terms followed the predicted order (1) vertical, (2) horizontal-frontal, (3) horizontal-lateral, in the early years. However, it was concluded that since the horizontal-frontal terms lagged behind the others in later childhood and adulthood, perceptual difficulty alone was not an adequate explanation. In addition, no support was found for Clark's notion that linguistic terms associated with the ‘positive’ end of each spatial dimension will be acquired earlier than those associated with the ‘negative’ end.

Some word-finding problems (recorded on tape) of a Dutch two-year-old are reported. The child's attempts at retrieving a certain target form show many characteristics which are typical for ‘tip-of-the-tongue’ experiences. During his lexical search the child produces malapropisms and a blend. The speech errors are analysed, and implications for the character of early lexical organization and the order of lexical form/meaning acquisition are discussed.

This study tracked the order in which ten beginning spellers (M age=5 ; 05; SD=0·21 years) mastered the correct spellings of common inflectional suffixes in English. Spellings from children's journals from kindergarten and grade 1 were coded. An inflectional suffix was judged to be mastered when children spelled it accurately in 90 percent of the contexts in which it was grammatically required, a criterion used to study the order of acquisition of grammatical morphemes in oral language. The results indicated that the order in which children learned to spell inflectional suffixes correctly is similar to the order in which they learn to use them in oral language, before school age. Discrepancies between the order of mastery for inflectional suffixes in written and oral language are discussed in terms of English spelling conventions, which introduce variables into the spelling of inflected words that are not present in oral language.

As Peters points out in this and other work, the treatment of filler syllables continues to be problematic. To the extent that theoretical linguistic approaches to language acquisition have addressed the problem of morphology at all, this has been almost entirely in the domain of syntax. Thus, the phonological and prosodic characteristics of filler syllables in children's early speech have been largely ignored, the assumption being that the appearance of grammatical morphemes is ‘triggered’ by the maturation of syntactic representations (e.g. Radford, 1990). If this were the case, we would not expect to find crosslinguistic differences in the timing of the acquisition of determiners (Lleó & Demuth, 1999), nor the variable appearance of grammatical morphemes in some contexts and not others (Demuth, 1994, Gerken, 1996). These cases of crosslinguistic and within-language variation call for a more comprehensive account of early morpheme acquisition which can explain their variable presence or absence.

It is not well understood how grammar emerges in very-low-birth-weight (VLBW) children. The main aim of the present study was to gain information on the emergence of grammar in this group at 2 ; 0. The Finnish version of the Communicative Development Inventory was used to collect data from VLBW children (N = 156) and full-term controls (N = 146). At a group level, the grammatical skills of the VLBW children were significantly weaker than those of the controls. However, when the effect of lexicon size and premature birth on the emergence of grammar was analyzed in detail, few significant differences were found between the groups. The results suggest that even though grammar emerges more slowly for the VLBW children, it emerges in a manner comparable to that of the controls, when the effect of lexicon size is taken into consideration.

This paper sets out to examine two findings reported in the literature: one, that during the one-word stage a child's word productions are highly phonetically variable, and two, that the one-word stage is qualitatively distinct from subsequent phonological development. The complete set of word forms produced by a child at the one-word stage were collected and analysed both cross-sectionally (month by month) and longitudinally (looking for changes over time). It was found that the data showed very little variability, and that phonological development during the period studied was qualitatively continuous with subsequent development. It is suggested that the phonologically principled development of this child's first words is related to his late onset of speech.

The impact of input frequency (IF) and functional load (FL) of segments in the ambient language on the acquisition order of word-initial consonants is investigated. Several definitions of IF/FL are compared and implemented. The impact of IF/FL and their components are computed using a longitudinal corpus of interactions between thirty Dutch-speaking children (age range: 0 ; 6–2 ; 0) and their primary caretaker(s). The corpus study reveals significant correlations between IF/FL and acquisition order. The highest predictive values are found for the token frequency of segments, and for FL computed on minimally different word types in child-directed speech. Although IF and FL significantly correlate, they do have a different impact on the order of acquisition of word-initial consonants. When the impact of IF is partialed out, FL still has a significant correlation with acquisition order. The reverse is not true, suggesting that the acquisition of word-initial consonants is mainly influenced by their discriminating function.

We studied spontaneous speech noun-phrase production in eight French-speaking children with SLI (aged 5 ; 0 to 5 ; 11) and controls matched on age (4 ; 10 to 5 ; 11) or MLU (aged 3 ; 2 to 4 ; 1). Results showed that children with SLI prefer simple DP structures to complex ones while producing more substitution and omission errors than controls. The three groups also showed distinct error patterns. Children with SLI appeared to have difficulty with phonological processes involved in liaison, elision, and contraction, whereas control children tended to make more lexical errors. These data support models of reduced morphosyntactic and syntactic abilities in this population, and suggest that morphophonological processes should also be integrated into descriptive models of SLI.

Generic language (Owls eat at night) expresses knowledge about categories and may represent a cognitively default mode of generalization. English-speaking children and adults more accurately recall generic than quantified sentences (All owls eat at night) and tend to recall quantified sentences as generic. However, generics in English are shorter than quantified sentences, and may be better recalled for this reason. The present study provided a new test of the issue in Spanish, where generics are expressed with an additional linguistic element not found in certain quantified sentences (Los búhos comen de noche ‘Owls eat at night’ [generic] vs. Muchos búhos comen de noche ‘Many owls eat at night’ [quantified]). Both preschoolers and adults recalled generics more accurately than quantified sentences, and quantified sentences were more often recalled as generic than the reverse. These findings provide strong additional evidence for generics as a cognitive default, in an understudied cultural context.

Maternal responsive and directive speech to children at ages 0;10 and 2;0 was investigated by applying a procedure first introduced by Flynn and Masur (2007) to a new language community (Finnish). The issues examined were consistency and stability over time, and also the role of responsiveness and directiveness in child linguistic development at 1;0 and 2;6. The measures of maternal speech from each age were used to predict the results of the subsequent linguistic assessment. Negative correlations between responsive and directive utterances were found at both ages. The frequencies of responsive utterances and supportive directives increased over time. Responsiveness was positively, and intrusive directiveness negatively, related to child early comprehensive skills and the use of symbolic actions and communicative gestures. By contrast, no relations were found between responsiveness and directiveness and children's later linguistic capacities.

In her interesting article, Stoel-Gammon (this issue) reviews studies concerning the interactions between lexical and phonological development. While the focus of the review is on vocabulary production from children acquiring American English, she also suggests that cross-linguistic research be undertaken to examine how universal and language-specific properties affect the interaction between lexical and phonological acquisition. In this regard, Stoel-Gammon referred to the study of Bleses et al. (2008) who found differences in receptive vocabulary development across languages, based on norming studies for the Communicative Development Inventories (Fenson, Marchman, Thal, Dale, Reznick & Bates, 2007). Bleses et al. showed that Danish children were slower in the early comprehension of words (and phrases). It was hypothesized that the phonetic structure of Danish may account for the difference in receptive vocabulary skills in this population (Bleses & Basbøll, 2004).

Before the beginning of the Journal of Child Language in 1974 three technological innovations had set the stage for a fundamental expansion and revision of our understanding of the processes of child language acquisition. Portable audio and video recorders changed both the quantity and quality of data. Computers made it possible to store and search large corpora, to rapidly carry out statistical analyses of the distribution of linguistic forms and their changes over time, and to simulate models of acquisition. This essay is a personal and historical overview of the unexpected consequences of those technological innovations for the study of child language. In looking to the future, another tool, linguistic typology, is essential for building models of language acquisition.

Lexical stress is the contrast between strong and weak syllables within words. Ballard et al. (2012) examined the amount of stress contrastivity across adjacent syllables in word productions of typically developing three- to seven-year-olds and adults. Here, eight- to eleven-year-olds are compared with the adults from Ballard et al. using acoustic measurements of relative contrast in duration, peak intensity, and peak fundamental frequency of the vowels within the initial two syllables of each word. While eight- to eleven-year-olds are closer to adult-like stress contrastivity than three- to seven-year-olds, they are not yet adult-like in terms of the intensity contrast for words beginning with a weak syllable.

We report three studies (one corpus, two experimental) that investigated the acquisition of relative clauses (RCs) in Finnish-speaking children. Study 1 found that Finnish children's naturalistic exposure to RCs predominantly consists of non-subject relatives (i.e. oblique, object) which typically have inanimate head nouns. Study 2 tested children's comprehension of subject, object, and two types of oblique relatives. No difference was found in the children's performance on different structures, including a lack of previously widely reported asymmetry between subject and object relatives. However, children's comprehension was modulated by animacy of the head referent. Study 3 tested children's production of the same RC structures using sentence repetition. Again we found no subject–object asymmetry. The pattern of results suggested that distributional frequency patterns and the relative complexity of the relativizer contribute to the difficulty associated with particular RC structures.