The amount of influence that a learner's native language has on the acquisition of a second language is an issue which has received considerable attention in research on second language acquisition. The thesis of this paper is that, within the context of the Interlanguage Hypothesis (Selinker 1972) and the Markedness Differential Hypothesis (Eckman 1977), some important properties of a learner's interlanguage (IL) can be predicted.
More specifically, it is shown that speakers of Cantonese and Japanese internalize different IL rules in attempting to deal with English word-final voice contrasts. Whereas speakers of Cantonese devoice word-final obstruents in the target language, Japanese speakers insert a word-final schwa after the voiced obstruent. However, each of these rules can be correlated with facts about the phonology of the native language, supporting the conclusion that some important aspects of ILs can be predicted on the basis of a comparison of the native and target languages.