Earlier version of this paper was read at the Second International Congress of Applied Linguistics, Cambridge, England, September 1969. (VM)

Tests to discover the nature of the second language learner's language are discussed. Such tests are based on the assumptions that the development of the system of the foreign language in the learner follows certain regular patterns, and that the learner's grammar is essentially systematic at any stage of his learning. (RM)

A contrastive analysis should describe the different processes of conceptualization in the languages under consideration. Furthermore, a detailed semantic analysis of linguistic items should be undertaken to discover perceptual strategies which force the speaker to use these items. Research in psycholinguistics is valuable in these tasks. (DB)

This article offers insights into mnemonic strategies ("mental elaboration") of foreign-language learners, with implications for vocabulary learning in the target language. (DB)