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.

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.

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.

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.

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.

This study was designed to examine factors associated with literal interpretations of homonyms. Participants were 212 second graders, ages 7;0–8;11, who listened to a story containing 16 key words. The key words were homonymous words (‘pseudo-homonyms’), nonsense words, or familiar words used accurately. While listening to the story, children selected an illustration of each key word. Later, they were asked to recall the key words and to justify their picture selections. There was no association between interpretation and recall accuracy for nonsense words or familiar words used accurately; however, children who accurately recalled a homonymous key word were more likely to interpret the homonym ‘literally,’ relative to children who failed to recall the key word. Yet most of the children who correctly interpreted the pseudo-homonyms also correctly interpreted these key words. Most children correctly recalled the story context regardless of key word type, but whereas correct recall of context predicted accurate interpretation of nonsense words and familiar words used accurately, it did not do so for homonyms. Children made equivalent numbers of literal and accurate interpretations of homonyms, even when correctly recalling context. Children's justifications for their word interpretations implicated the role of metacognitive skills, particularly in terms of selective attention, as a factor influencing homonym interpretation.

Thirty-six three- to four-year-old children were tested to assess whether hearing a word-referent link from an ignorant speaker affected children's abilities to subsequently link the same word with an alternative referent offered by another speaker. In the principal experimental conditions, children first heard either an ignorant or a knowledgeable speaker link a novel word with one of three toys. The first speaker's labelling episode was followed by a second in which a different speaker used the same novel label but for a different toy. There was also a Base-line condition which was the same as the experimental condition involving the ignorant speaker except that she did not associate the novel label with a referent. When tested for comprehension of the novel label, children selected the FIRST speaker's toy at high levels when the first speaker was knowledgeable, but selected the SECOND speaker's toy when the first speaker was ignorant. These findings suggest that children's experience with the ignorant speaker did not affect their abilities to learn a subsequently presented alternative word-referent link. These findings are discussed in terms of understanding the mechanisms by which children adapt their word-learning in line with speakers' knowledge states.