M. Canale and M. Swain's (1980) model of communicative competence identifies three levels of analysis: what they call grammatical, sociolinguistic and strategic. The chapter provides examples of some important areas of systemic competence, and nearly all the examples relate to the English language. It looks at semantics, not of syntactic structures but of individual words, or lexis. Words are very important in language learning. Morphemes are the building blocks of words. Learners of English as a foreign language may often find it relatively easy to learn what a word denotes – what it describes in some 'factual', 'basic' way. Few teachers would give a lecture to explain the difference between voiced and unvoiced sounds. The 'plural pronunciation rules' are about how sounds behave when they join together into larger units. The fact that using rules of discourse in a non-standard way can be blamed on slapdashness makes them particularly serious in some contexts.