Abstract
In this study research was carried out into the acquisition of the strict adjacency of the verb and its object, one of the traits of English, on the foundation of the hypothesis built by UG theories, with respect to three factors: grammatical competence, linguistic knowledge, and linguistic performance. The result shows that the more adverbs are inserted between verbs and their objects, the less correctly the subjects judge the grammaticality of the sentences in question, and the longer it takes them to make their judgments. Above all, it shows that resetting the parameters of strict adjacency is not a successful procedure, as was expected, and can not be acquired perfectly, especially by the group with a lower proficiency in grammatical competence. At the same time it also suggests that research on language acquisition include not only linguistic knowledge but linguistic performance in its models, and that it is necessary to design teaching and evaluating methods which attach great importance to the response time for processing and judging English sentences, which hints at something that should be improved in the teaching of English in Japan.
