The learner's constant objective in language acquisition is to reduce the gap between his language performance and that of native speakers of the target language. The progress towards this goal is not necessarily evenpaced or direct. The learner may make false assumptions and will find it very difficult to get rid of them; he may even slide back in his proficiency. Apart from these irregularities, language acquisition in principle proceeds from one learner variety to the next in gradual approximation of the target variety – until this process comes to a halt. With luck, the remaining discrepancy may be negligible and hence scarcely noticeable. In general, however, most learners end up with a language variety which contrasts strongly with the target variety. Of course, not all learners may be aware of this: some are unable to tell the difference and harbour illusions as to their language proficiency. Others will be generally aware of their imperfections but unable to pinpoint them with the precision needed for subsequent amelioration. Progress in language acquisition requires the learner to match continuously his own language performance against the standards of the target language speakers. This matching task confronts the learner at all stages of the process: at the beginning the discrepancy is striking and cannot go unnoticed; the smaller it becomes, towards the end of the process, the greater the matching problem.

This chapter deals with certain aspects of the matching problem. Although not very much empirical evidence is currently available on this matter, it is possible to offer some mostly theoretical considerations.