Most studies of code switching have focussed on its use in informal, oral settings, but written examples also occur. The Castilian-Hebrew switching in the Jewish taqqanot ‘statutes’ of Valladolid, Spain, written in 1432, provides important data for testing the different constraints proposed in studies on code switching. Examples of switches between determiner-noun, preposition-noun, possessive-noun, quantifier-noun, and ser-participle indicate that the code switches in the taqqanot usually conform to some of the constraints already proposed: the Free Morpheme Constraint, the Equivalence Constraint, and the Closed-Class Constraint. At the same time, the analysis of these medieval switches confronts the same unresolved issues as other studies, for instance, the need to adequately distinguish between borrowings and code switches and the question of whether bilingual utterances always have an identifiable matrix language.

Prior research has suggested that Korean might constitute an exception to the proposed notion of the universality of the rhyme. Five experiments were performed to test this hypothesis out with native speakers of that language. Four different experimental tasks were employed: a global sound similarity judgement task, a concept formation task, a unit reduplication task, and a list recall task. In all cases the results indicate that Korean syllables were seen to contain a cohesive CV or body unit, in contrast to the VC of rhyme unit of English. The final experiment, involving list recall, was considered especially important, as it involved the testing of preliterate children, whose results could not have been influenced by knowledge of the orthography. An attempt is made to explain these findings in terms of intrinsic properties of the syllables in the two languages. The theoretical significance of this research is also discussed.