This article exemplifies language-internal explanation. It seeks to document and to explain the inability of Russian impersonal clauses to be infinitival. We argue that this gap is the consequence of two independent facts of Russian grammar: a case restriction on a silent expletive pronoun and the requirement that subjects of infinitival clauses be dative. These clash in infinitival contexts, which explains the gap. The explanation is language-internal in that it relies on no putatively universal principles. At the same time, each type of device posited is needed independently in the grammars of other languages. Our result bears on the issue of what language-particular properties expletives may have, on the issue of whether silent expletives exist, and on the more general theoretical issue of whether clauses are required to have subjects universally.

There are two types of truncation that yield shortening of a morphological constituent, fake truncation (templatic) and true truncation (a-templatic, subtractive). This article provides an analysis of true truncation in colloquial Hebrew imperatives. It is shown that true truncation cannot target a designated phonological unit, since in some forms CV is truncated and in others only V. In addition, there are cases where truncation is blocked. The framework of optimality theory adopted here allows a unified account of the data in terms of constraint interaction. It is argued that an antifaithfulness truncation constraint, which must be morphological, interacts with both faithfulness and markedness constraints. Truncation is minimized to one segment by a general antideletion faithfulness constraint, but markedness constraints may impose truncation of more than one segment. There are cases where truncation is blocked, which suggests that the truncation constraint is violable. The discussion includes regular and irregular verbs and instances of free variation.

The representation of regular morphological processes has been the subject of much controversy, particularly in the debate between single and dual route models of morphology. I present a model of morphological learning that posits rules and seeks to infer their productivity by comparing their reliability in different phonological environments. The result of this procedure is a grammar in which general rules exist alongside more specific, but more reliable, generalizations describing subregularities for the same process. I present results from a nonce-probe (wug) experiment in Italian, in which speakers rated the acceptability of novel infinitives in various conjugation classes. These results indicate that such subregularities are in fact internalized by speakers, even for a regular morphological process.

This article is devoted to the anatomy of an unnatural syntactic change. It presents the life history of the Welsh predicative particle yn—its diachronic genesis in Indo-European, its synchronic status, and (much more centrally) what happened along the way, and why what happened happened specifically in Welsh. Synchronically, I give syntactic, semantic, typological, and textual arguments—some rather new—that both predicative yn and verb-periphrastic yn are adverbializers and count as grammatically polysemous subsenses of the preposition 'in'. Diachronically, I argue that the pan-Celtic adverbializing particles yn/ent/int/ind (thence ultimately Welsh predicative yn) all derive from an article-like demonstrative sindo-/sinto- (and not from a preposition endo/ento). Radical categorial changes must therefore have occurred. I trace these changes and motivate a multistage metanalysis (not involving grammaticalization) whereby the original quasi-article first became an adverbializer and then was attracted into the orbit of the preposition 'in'. Though each microstage in the process makes good structural sense vis-à-vis the evolving système of the language, the achieved macrochange is highly unnatural.