An account of grammatical acquisition is developed within the parameter setting framework applied to a generalized categorial grammar (GCG). The GCG is embedded in a default inheritance network yielding a natural partial ordering (reflecting generality) of parameters that determines a partial order for parameter setting. Computational simulation shows that several resulting acquisition procedures are effective on a parameter set expressing major typological distinctions based on constituent order, and defining 70 distinct full languages and over 200 subset languages. The effects on acquisition of inductive bias, that is, of differing initial parameter settings, are explored via computational simulation.

Computational simulation of populations of language learners and users instantiating the acquisition model shows that: (1) variant acquisition procedures, with differing inductive biases, exert differing selective pressures on the evolution of language(s); and (2) acquisition procedures will evolve towards more efficient variants in the environment of adaptation. The reciprocal evolution of language acquisition procedures and of languages creates a genuinely coevolutionary dynamic, despite the relative speed of linguistic selection for language variants compared to natural selection for variant language acquisition procedures.

In most standard dialects of English, there is a gap in the paradigm of the verb be where we expect to find amn't. But how do we know that this gap exists, since learners have no positive evidence that amn't is ungrammatical? It is even more puzzling since there is no gap when the subject is inverted (aren't I...?). Familiar explanations for this gap fail; in particular, it cannot be the result of conservative acquisition strategies. The explanation offered here is based crucially on a combination of multiple-default inheritance and function-based morphology, as embodied in word grammar. The gap is due to a Nixon-diamond conflict between two competing values for the same morphological function required by the categories negative and first-person. The inverted form is supplied by stipulation because of the functional pressure to supply a ‘casual’ form. Various dialect alternatives to the Standard English pattern are also considered. The success of this explanation shows that language must use default inheritance, multiple nonorthogonal inheritance, and morphological functions.

We attempt to demonstrate that the substitution of a foreign segment in the borrowings of our database, which includes 14,350 segmental malformations from French and English loanwords in eight distinct languages, involves its replacement by a single native segment. This tendency is so strong in our database as to be virtually exceptionless, except where nasal vowels are concerned. These vowels are systematically adapted as an oral vowel followed by a nasal consonant (VN), a process we call unpacking. We document this process and suggest that it results from the fact that contrastive nasal vowels are fundamentally biphonemic, that is they have two root nodes. The influence of orthography is refuted, and a number of apparent counterexamples where segments other than nasal vowels seem to unpack are reanalyzed in terms of independent native processes.

The German Perfekt has two quite different temporal readings, as illustrated by the two possible continuations of the sentence Peter hat gearbeitet in i, ii, respectively:

(i) Peter hat gearbeitet und ist müde.

Peter has worked and is tired.

(ii) Peter hat gearbeitet und wollte nicht gestört werden.

Peter has worked and wanted not to be disturbed.

The first reading essentially corresponds to the English present perfect; the second can take a temporal adverbial with past time reference (‘yesterday at five’, ‘when the phone rang’, and so on), and an English translation would require a past tense (‘Peter worked/was working‘). This article shows that the Perfekt has a uniform temporal meaning that results systematically from the interaction of its three components—finiteness marking, auxiliary and past participle—and that the two readings are the consequence of a structural ambiguity. This analysis also predicts the properties of other participle constructions, in particular the passive in German.

Der Alte folgte der Leiche und die Söhne, Albert vermocht's nicht. Man fürchtete für Lottens Leben. Handwerker trugen ihn. Kein Geistlicher hat ihn begleitet.

Goethe, Werthers Leiden—

This article attempts to provide a precise definition for topic and to derive most of the properties of topic from this definition. The main assumption is that the topic-comment construction is a syntactic device employed to fulfill certain discourse functions. Topic is always related to a position inside the comment. Since topic has no independent thematic role but always depends on an element inside the comment for its thematic role, it has no syntactic function of its own. This dependence relationship is subject to locality constraints.

In this article we argue that there is a large class of expressions, typified by plastic flower, stuffed animal and kosher bacon, that have a unique semantics combining compositional, idiomatic and decompositional interpretation. These expressions are compositional because their constituents contribute their meanings to the meanings of the wholes; they are idiomatic because their interpretation involves assigning dictionary entries to nonterminal elements in their syntactic structure; and they are decompositional because their meanings have proper parts that are not the meanings of any of their syntactic constituents. We argue that extensionalist semantics, on which the meaning of an expression is a function from domains to extensions in those domains, cannot provide an adequate account of the semantics of these expressions, and that supplementation with a theory of pragmatic interpretation does not improve the situation. We show how our account explains the intensionality and the productivity of these expressions.