This article provides empirical evidence against the claims that [voice] is a privative feature and that word-internal devoicing can occur in a language without word-final devoicing. The study of voice patterns in a number of languages shows that the feature value [– voice] although it is the unmarked value of the laryngeal feature [voice], can be active phonologically in a fashion parallel to the marked value [+ voice]. Across languages, voice assimilation may occur independently of devoicing and, although it normally affects both [+voice] and [– voice], it may affect only one value in some languages.

One aspect of the relationship between meaning and interaction is explored here by taking the English particle actually, which is characterized by flexibility of syntactic position, and investigating its use in a range of interactional contexts. Syntactic alternatives in the form of clause-initial or clause-final placement are found to be selected by reference to interactional exigencies. The temporally situated, contingent accomplishment of utterances in turns and their component turn-constructional units shows the emergence of meaning across a conversational sequence; it reveals syntactic flexibility as both a resource to be exploited for interactional ends and a constraint on that interaction.

We explore the predictors of early mastery versus error in children's acquisition of American Sign Language. We hypothesize that the most frequent values for a particular parameter in prelinguistic gesture will be the most frequent in early signs and the most likely sources of substitution when signing children make errors. Analyses of data from a longitudinal study of the prelinguistic gestures of five Deaf and five hearing children and a longitudinal study of four Deaf children's early signs have revealed evidence of significant commonalities between prelinguistic gesture and early sign. This apparent continuity between prelinguistic gesture and early sign reflects constraints operating on the infant—in all likelihood, motoric constraints—that seem to persist into the first-word period in both major language modalities. In sign, as in speech, the production of first signs uses building blocks that are available to the prelinguistic child.

The existence of substantive parametric variation in syntax, as characterized in Chomsky 1981, has been questioned in the more recent generative literature, notably in Borer 1984, Fukui 1986, and Chomsky 1993. This article provides converging evidence from child language acquisition and comparative syntax for the existence of a syntactic parameter in the classical sense of Chomsky 1981, with simultaneous effects on syntactic argument structure (e.g., verb-particle constructions) and complex word-formation (root compounding). The implications are first that syntax is indeed subject to points of substantive parametric variation as envisioned in Chomsky 1981, and second that the time course of child language acquisition is a potentially rich source of evidence about the innate constraints on language variation.

I am grateful to Juan Uriagereka (2000) for his thorough and thoughtful review of my book The Origins of Complex Language (henceforth Origins; Carstairs-McCarthy 1999). The book tackles fundamental questions about the relationship among syntax, semantics, and cognition, and Uriagereka is not persuaded by all my suggestions about the prehistory of this relationship. I will not pursue these large issues here; rather, I want to address a more circumscribed issue that is nevertheless crucial to the argument of the book, so that my failure to discuss it is an important omission, as Uriagereka points out. This issue is whether the syllable, as a unit of phonological description, is modality-neutral (so as to be equally at home, with fundamentally the same sense, in descriptions of signed and spoken languages), or whether the syllables of signed and spoken languages are really different phenomena, so that the use of the term SYLLABLE for both draws attention to resemblances that are more accidental than fundamental. I will argue that the evidence supports the latter view more strongly than the former; therefore, when discussing language evolution, it is legitimate to appeal (as I do) to aspects of spoken syllables that are undoubtedly modality-dependent, such as their physiological underpinnings in the vocal apparatus.

Before addressing this issue directly, I would like to summarize briefly why it is important in the context of my book. Second, by way of reassurance, I will explain why the conclusion that I reach does not belittle sign languages, nor imply any old-fashioned skepticism about their entitlement to be recognized as real manifestations of the human language capacity.