This article proposes a new way of understanding grammatical status and grammaticalization as distinctive types of linguistic phenomena. The approach is usage-based and links up structural and functional, as well as synchronic and diachronic, aspects of the issue. The proposal brings a range of previously disparate phenomena into a motivated relationship, while certain well-entrenched criteria (such as ‘closed paradigms‘) are shown to be incidental to grammatical status and grammaticalization. The central idea is that grammar is constituted by expressions that by linguistic convention are ancillary and as such discursively secondary in relation to other linguistic expressions, and that grammaticalization is the kind of change that gives rise to such expressions.

Children (aged five-to-six and nine-to-ten years) and adults rated the acceptability of well-formed sentences and argument-structure overgeneralization errors involving the prepositional-object and double-object dative constructions (e.g. Marge pulled the box to Homer/Marge pulled Homer the box). In support of the entrenchment hypothesis, a negative correlation was observed between verb frequency and the acceptability of errors, across all age groups. Adults additionally displayed sensitivity to narrow-range semantic constraints on the alternation, rejecting double-object dative uses of novel verbs consistent with prepositional-dative-only classes and vice versa. Adults also provided evidence for the psychological validity of a proposed morphophonological constraint prohibiting Latinate verbs from appearing in the double-object dative. These findings are interpreted in the light of a recent account of argument-structure acquisition, under which children retreat from error by incrementally learning the semantic, phonological, and pragmatic properties associated with particular verbs and particular construction slots.

The source of syntactic island effects has been a topic of considerable debate within linguistics and psycholinguistics. Explanations fall into three basic categories: grammatical theories, which posit specific grammatical constraints that exclude extraction from islands; grounded theories, which posit grammaticized constraints that have arisen to adapt to constraints on learning or parsing; and reductionist theories, which analyze island effects as emergent consequences of non-grammatical constraints on the sentence parser, such as limited processing resources. In this article we present two studies designed to test a fundamental prediction of one of the most prominent reductionist theories: that the strength of island effects should vary across speakers as a function of individual differences in processing resources. We tested over three hundred native speakers of English on four different island-effect types (whether, complex NP, subject, and adjunct islands) using two different acceptability rating tasks (seven-point scale and magnitude estimation) and two different measures of working-memory capacity (serial recall and n-back). We find no evidence of a relationship between working-memory capacity and island effects using a variety of statistical analysis techniques, including resampling simulations. These results suggest that island effects are more likely to be due to grammatical constraints or grounded grammaticized constraints than to limited processing resources.

That there is a theoretical distinction between context-dependent and context-independent aspects of utterance interpretation has become a standard assumption in current theories of meaning; however, how and where to draw this distinction has been the subject of considerable debate. In the current study, we investigate whether speakers can systematically distinguish between what is said and what is implicated (Grice 1989 [1967]) using a novel truth-value judgment paradigm across a wide range of implicature types. We found that, by providing participants with a clear set of judgment criteria, including the adoption of an objective third-person perspective, we were able to enhance their ability to distinguish conversational implicature from truth-conditional meaning. In addition, we found that none of the implicature types we investigated was either consistently incorporated into or consistently excluded from what is said. Instead, our findings revealed considerable variation in frequency of incorporation across implicature types in ways that do not correspond straightforwardly to the various taxonomies of implicature types proposed in the literature.

Linguists have increased their documentation efforts in response to the sharp decline in the number of languages. Greater awareness and new sources of funding have led to an upsurge in language documentation. While individual languages make unique contributions to the world's linguistic heritage, language families, by virtue of their shared heritage, have related contributions to make. The endangerment of entire families, while implied by the loss of language, has not been explored to date. Here, we examine estimates of how many linguistic stocks (the largest subgroups of related languages that are reconstructable) consist entirely of endangered languages and thus are endangered themselves. Our data set includes 372 stocks that had at least one living language in 1950. Our finding is that since that time, 15% of the world's linguistic stocks have become extinct and another 27% are now moribund in that direct estimates of endangerment indicate that no member languages are being learned by children. For cases where direct estimates were not found, we used population as a proxy for endangerment. If, as many predict, a further 50% of the world's languages become extinct or moribund in this century, then an additional 25% of the linguistic stocks would be at risk of being lost. If 90% share this fate, only 11% of stocks would have at least one presumably ‘safe’ language. A comparison of the vitality of linguistic stocks by world areas yields the following ranking from worst to best: Americas, Pacific, Asia, Africa, Europe. Finally, some aspects of language that are unique to disappearing language stocks are outlined. Renewed efforts at documenting members of such stocks seem justified.