The acoustic-phonetic realizations of words can vary dramatically depending on a variety of within- and across-talker characteristics such as regional dialect, native language, age, and gender. Robust word learning requires that children are able to recognize words amidst this substantial variability. In the current study, perception of foreign-accented words was assessed in four- to seven-year-old children to test how one form of variability influences word recognition in children. Results demonstrated that children had less accurate word recognition than adults for both native- and foreign-accented words. Both adults and children were less accurate at identifying foreign-accented words compared to native-accented words with children and adults showing similar decrements. For children, age and lexicon size contributed to accurate word recognition.

This study compares homonym learning to novel word learning by three- to four-year-old children to determine whether homonyms are learned more rapidly or more slowly than novel words. In addition, the role of form characteristics in homonym learning is examined by manipulating phonotactic probability and word frequency. Thirty-two children were exposed to homonyms and novel words in a story with visual support and learning was measured in two tasks: referent identification; picture naming. Results showed that responses to homonyms were as accurate as responses to novel words in the referent identification task. In contrast, responses to homonyms were more accurate than responses to novel words in the picture-naming task. Furthermore, homonyms composed of common sound sequences were named more accurately than those composed of rare sound sequences. The influence of word frequency was less straightforward. These results may be inconsistent with a one-to-one form–referent bias in word learning.

Two studies investigating young readers' use of conjunctions are reported. In Study One, 145 eight- to ten-year-olds completed one of two narrative cloze tasks in which different types of conjunction were deleted. Performance for additive conjunctions was not affected by age in this study, but older children were more likely to select the target conjunction than were younger children for temporal, causal, and adversative terms. Performance was superior in the cloze task in which they were given a restricted choice of responses (three vs. seven). In Study Two, 35 eight- and nine-year-old good and poor comprehenders completed the three-choice cloze task. The poor comprehenders were less likely to select the target terms in general. Sentence-level comprehension skills did not account for their poor performance. The results indicate that understanding of the semantic relations expressed by conjunctions is still developing long after these terms are used correctly in children's speech. The findings are discussed in relation to the role of conjunctions in text comprehension.

The aim of the study presented here was to examine variations in the forms and functions of agreement and refusal messages – which can be solely gestural, solely verbal, or combined gestural and verbal – by thirty children aged 1;4, 2;0, and 3;0 (ten in each age group) observed at home during an interaction with their mother. The results showed that even though verbal forms were the predominant ones as a whole, gestural forms were carried over into the linguistic period, and for the youngest children, constituted the sole means of agreeing and refusing. They also showed that the most frequently expressed function was assertion.

Studies of comprehension of the quantifiers all and more are reported. The subjects were children between the ages of three and five. There were two main conditions. In one of these the objects to which the quantifiers related were enclosed in containers which either were or were not filled by the objects. In the other no containers were present. These conditions yielded substantially different response patterns. The relation of the findings to those typically obtained from Piagetian conservation tasks is discussed; and the implications for theories of semantic development are considered.

Two-year-olds learn language quickly but how they exploit adult input remains obscure. Twenty-nine children aged 2;6 to 3;2, divided into three treatment groups, participated in an intervention experiment consisting of four sessions 1 week apart. Pre- and post-intervention sessions were identical for all children: children heard a wh-question and attempted to repeat it; a ‘talking bear’ answered. That same format was used for the two intervention sessions for children in a quasicontrol condition (Group QC). Children receiving modelling (Group M) heard a question twice before repeating it; those receiving implicit correction (Group IC) heard a question, attempted to repeat it, and heard it again. All groups improved in supplying and inverting an auxiliary for target questions with trained auxiliaries. Only experimental children generalized to auxiliaries on which they had not been trained. Very little input, if concentrated but varied, and presented so that the child attends to it and attempts to parse it, is sufficient for the rapid extraction and generalization of syntactic regularities. Children can learn even more efficiently than has been thought.

It is often assumed that children go through a stage in which they systematically overapply irregular past tense patterns to inappropriate verbs, as in wipe-wope, bring-brang, trick-truck, walk-has walken. Such errors have been interpreted both as reflecting over-use of minor grammatical rules (e.g. ‘change i to a’), and as reflecting the operation of a connectionist pattern associator network that superimposes and blends patterns of various degrees of generality. But the actual rate, time course, and nature of these errors have never been documented. We analysed 20,000 past tense and participle usages from nine children in the CHILDES database, looking for overapplications of irregular vowel-change patterns, as in brang, blends, as in branged, productive suffixations of -en, as in walken, gross distortions, as in mail-membled, and double-suffixation, as in walkeded. These errors were collectively quite rare; children made them in about two tenths of one per cent of the opportunities, and with few stable patterns: the errors were not predominantly word-substitutions, did not occur predominantly with irregular stems, showed no consistency across verbs or ages, and showed no clear age trend. Most (though not all) of the errors were based closely on existing irregular verbs; gross distortions never occurred. We suggest that both rule-theories and connectionist theories have tended to overestimate the predominance of such errors. Children master irregular forms quite accurately, presumably because irregular forms are just a special case of the arbitrary sound-meaning pairings that define words, and because children are good at learning words.

The English orthography is morphophonemic: spellings encode both morphemes and phonemes. Questions of the starting point and extent of young children's understanding of the link between morphemes and spelling are important for theories of spelling development. We conducted two experiments to address these issues. In Experiment 1, 65 six- to eight-year-old English-speaking children spelled just the first sections of inflected, derived and control words. Their spelling of these first segments was better in inflected and derived words than in control words. The findings were replicated in Experiment 2 with 78 six- to eight-year-old children spelling a greater number of items. These two studies converge on the conclusion that, in specific testing situations, six- to eight-year-old children appreciate the role of root morphemes in the spelling of both inflected and derived words. These results are discussed in relation to current models of spelling development.

The influence of frequency of occurrence in input upon early lexical acquisition was examined within an experimental paradigm. Twelve children (1; 0·21 to 1; 3·15) were presented with 16 contrived lexical concepts, each involving a nonsense word and four referents, over ten experimental sessions. Within each concept two exemplars were presented frequently and two were presented infrequently. Overall the children named more frequently presented exemplars than infrequently presented exemplars. However, when the absolute number of presentations was held constant, distributed (infrequent) presentations led to greater acquisition than massed (frequent) presentations.

An experiment on children between 2; 0 and 7; 0 showed that they initially interpret the same X to mean ‘same kind’ in contexts where it actually means ‘same one’. This led to a critical evaluation of Piaget's implicit contention that young children are using determiners anaphorically. Stress is placed on the linguistic rather than conceptual component of children's behaviour in experiments involving questions of the type: Is it the same X? It is argued that language is not only the tool of intelligence for representing ongoing cognitive development, but that it is also a problem area for children within its own right. It is suggested that the importance of young children's processing procedures on the linguistic environment has hitherto been underestimated in Piaget's interactive epistemology.

The past and present state of the empiricism–nativism issue is analysed. Empiricist philosophical doctrine (‘no innate ideas’) distinguished idea from structure or mechanism. However, Chomsky's conception of innate linguistic universals erased this distinction. The elimination left would-be empiricists without a coherent and defensible position. I argue that the issue remains alive primarily because of tension between two scientific tasks that face students of development. One is to discover what is cognitively and linguistically primitive, a task that encourages nativism. However, nativism is ultimately unsatisfactory because it systematically neglects the other task, which is to account for development, including the emergence of postulated innate primitives. To account for such primitives, it is necessary to relate them to particular central nervous System structures in such a way as to explain how the structure has the particular cognitive effects that define the primitive. That is likely to be difficult, and I show how the study of learning – much neglected in recent years – can help by reducing the number and type of innate primitives whose origin must be explained in that way.

This study investigated different accounts of children's acquisition of non-subject wh-questions. Questions using each of 4 wh-words (what, who, how and why), and 3 auxiliaries (BE, DO and CAN) in 3sg and 3pl form were elicited from 28 children aged 3;6–4;6. Rates of non-inversion error (Who she is hitting?) were found not to differ by wh-word, auxiliary or number alone, but by lexical auxiliary subtype and by wh-word+lexical auxiliary combination. This finding counts against simple rule-based accounts of question acquisition that include no role for the lexical subtype of the auxiliary, and suggests that children may initially acquire wh-word+lexical auxiliary combinations from the input. For DO questions, auxiliary-doubling errors (What does she does like?) were also observed, although previous research has found that such errors are virtually non-existent for positive questions. Possible reasons for this discrepancy are discussed.

Observational/correlational research has established that children in stage 5 object permanence development use words that refer to the visible movement of objects, while it is not until stage 6 that they use words referring to the invisible movement of objects (e.g. gone). It is not clear, however, whether the cognitive competence evidenced by performance in the object permanence task is a prerequisite for these linguistic productions or whether they both emerge simultaneously from some underlying representation. The current study used a lexical training paradigm to teach object words, visible movement words, and invisible movement words to children at stage 5 and stage 6 object permanence development. Stage 6 children learned all three types of words equally well. Stage 5 children learned object and visible movement words, especially in comprehension, but did not learn the invisible movement word. These results indicate that the cognitive structures underlying performance in the object permanence task are genuine prerequisites for learning these types of words.

There are differences and similarities between Modern Standard Arabic (MSA) and spoken varieties of Arabic, in all language domains. To obtain preliminary insights into interactions between the acquisition of spoken and standard varieties of a language in a diglossic situation, we employed forced-choice grammaticality judgments to investigate morphosyntactic knowledge of MSA and the local variant of Palestinian Colloquial Arabic (PCA), in 60 Arabic-speaking children aged 6 ; 4 to 12 ; 4, from a school in Nazareth. We used morphosyntactic structures which either differed or were similar between PCA and standard Arabic. Children generally performed better on items presented in PCA than in standard Arabic, with the exception of constructions involving negation. Children performed better on items when the two constructions were similar in both language varieties. We discuss the results with respect to the multiple factors that affect acquisition in a diglossic situation, and relate our findings to the possibility of interference effects of diglossia on learning.

The notion of competence as it applies to child language is critically assessed in the light of evidence collected from a number of linguistic performances which share the same word-order rule. These performances – production, comprehension, judgment and correction – parallel Moravcsik's (1969) formulation of Chomsky's criteria for tacit knowledge of a rule, i.e. competence. It was found that these criteria are not all satisfied until the child is four or five years old, as the performances appear at very different points in time. Alternative criteria for tacit knowledge are suggested, with specific models of each performance replacing a general model of competence for early child speech.

Ostensive definitions of words are ambiguous as to their referent. In a study of 40 mother–infant dyads engaged in looking at picture-books, it was found that 95% of ostensive definitions referred to the whole object depicted, rather than to its parts, attributes or actions. On the rare occasions when mothers named parts of objects, they avoided misunderstanding of the level of reference either by naming the part immediately after naming the whole, or by including a reference to the whole in the definition of the part. What's that? questions are not used to request labelling of the part.

In order to isolate the properties of language whose development can withstand wide variations in learning conditions, we have observed children who have not had access to any conventional linguistic input but who have otherwise experienced normal social environments. The children we study are deaf with hearing losses so severe that they cannot naturally acquire spoken language, and whose hearing parents have chosen not to expose them to a sign language. In previous work, we demonstrated that, despite their lack of conventional linguistic input, the children developed spontaneous gesture systems which were structured at the level of the sentence, with regularities identifiable across gestures in a sentence, akin to syntactic structure. The present study was undertaken to determine whether one of these deaf children's gesture systems was structured at a second level, the level of the gesture – that is, were there regularities within a gesture, akin to morphologic structure?

We have found that (1) the deaf child's gestures could be characterized by a paradigm of handshape and motion combinations which formed a matrix for virtually all of his spontaneous gestures, and (2) the deaf child's gesture system was considerably more complex than the model provided by his hearing mother. These data emphasize the child's contribution to structural regularity at the intra-word level, and suggest that such structure is a resilient property of language.

The positive effects of shared book reading on vocabulary and reading development are well attested (e.g., Bus, van Ijzendoorn, & Pellegrini, 1995). However, the role of shared book reading in grammatical development remains unclear. In this study, we conducted a construction-based analysis of caregivers’ child-directed speech during shared book reading and toy play and compared the grammatical profile of the child-directed speech generated during the two activities. The findings indicate that (a) the child-directed speech generated by shared book reading contains significantly more grammatically rich constructions than child-directed speech generated by toy play, and (b) the grammatical profile of the book itself affects the grammatical profile of the child-directed speech generated by shared book reading.

The utterances of one French and one American infant at 0;5, 0;8, 0;11, and 1;2 were transcribed and acoustically analysed for syllable duration and vowel formant values. Both general and language-specific effects emerged in the longitudinal study. Initial similarities in the consonantal repertoires of both infants, increasing control in producing target F1 and F2 values, and developmental changes in babbling characteristics over time seem to reflect universal patterns. Yet the babbling of the infants differed in ways that appear to be due to differences in their language environments. Shifts in the infants' sound repertoires reflected phoneme frequencies in the adult languages. The English-learning infant produced more closed syllables, which is characteristic of English, than the French-learning infant. The French-learning infant tended to produce more regularly-timed nonfinal syllables and showed significantly more final-syllable lengthening (both characteristic of French) than the English-learning infant.