The main objective of the proposed research is to understand how the linguistic system continues to learn in adulthood. We will examine learning at two quite different levels: syntax and phonetics. Learning mechanisms in adults are not well understood at any level; it is also not clear that the mechanisms are the same across levels. Three groups of experiments will determine whether (i) implicit learning in adults requires meaning, (ii) learning requires explicit exposure to the correct underlying syntactic or phonetic structure (or if adults can use meaning to infer that structure), and (iii) whether learning serves comprehension and production in the same way, or whether there are functional differences between the two systems. We use several paradigms and measures of learning at each level: syntactic priming and phonetic convergence in production (each refers to the tendency of speakers to re-use structures that they have previously been exposed to), and syntactic fluency and phoneme identification in comprehension. Overall, this research will strengthen our knowledge of learning that results from both syntactic and phonemic processing, and the similarities (and differences) between the two. [unreadable] [unreadable]