The experiments discussed in this report are designed to explore the relationship between language and thought and implications for foreign language learning. Three basic issues are considered: whether or not thought and language are sufficiently distinct to require separate attention and planning as distinct factors in language teaching; the role of thought in foreign language performance; and means of introducing thought into language teaching, with an experimental check on its effect on learning and motivation. Five experiments are described along with their results, and the conclusions are reviewed. Thought and language are considered distinct; thought is central in language in maintaining unity, continuity, and relevance; and language is a symbolic system used to refer to thought. Findings on memory and recall are also presented. Examples from the experiments and a bibliography are provided. (Author/VM)