Immigrants from one dialect region to another acquire features of the new dialect with varying degrees of proficiency. In modern societies regional mobility is commonplace, and for modern dialectology, involved as it is with variability, mechanisms of change, and adaptation, it is a rich source of hypotheses. This article postulates eight general principles by which immigrants adapt dialectologically to their new surroundings, based mainly on results of a developmental study of six Canadian youngsters in two families who moved to southern England in 1983 and 1984, with supporting evidence from several other studies. The principles provide a set of empirically testable hypotheses about the determinants of dialect acquisition.

On the prevailing view of ultimate attainment in second language acquisition, native competence cannot be achieved by postpubertal learners. The present study offers convergent experimental evidence which suggests there are exceptions to this generalization. At the same time, early arrival in the host country—even if past puberty—correlates with attainment of native norms on a variety of measures. Also investigated are the loci of competence differences in the syntax of the target language (French). Contrary to findings by Coppieters 1987, experimental performance is not predicted by the status of a given linguistic variable as within or outside the theoretical domain of Universal Grammar.

A theme running through much of the functionalist literature in linguistics is that grammatical structure, to a considerable degree, has an ‘iconic’ motivation. This theme can be distilled into three rather distinct claims: (1) iconic principles govern speakers’ choices of structurally available options in discourse; (2) structural options that reflect discourse-iconic principles become grammaticalized; (3) grammatical structure is an iconic reflection of conceptual structure.

After presenting numerous examples from the functionalist literature in support of the idea that iconicity is widespread in language, I argue that claim (1) is irrelevant to generative grammar; claim (2), if correct, poses no challenge to generative grammar, despite a widespread belief to the contrary; and claim (3) has literally been built into standard versions of generative grammar. I go on to discuss the implications of iconic relations in language for the autonomy hypothesis and, at a more speculative level, for the evolution of language.