Some suggestions are offered for the teaching of idiomatic language. The relation between nonidiomatic and erroneous language in foreign-language learning is examined, and it is concluded that nonidiomatic sentences venture into the gray area of weak combinatorial probabilities between linguistic items. Idiomaticity is seen as a scale, with both conventionalized and original language having their place in discourse. The issue of appropriateness in context is crucial. Full-blown idioms represent firm collocations whose meaning is conventionalized and metaphorical. In proverbs, this meaning takes on an aphoristic quality. The underlying principle of metaphor provides a structural systematicity to the lexis, which extends far beyond full idioms into all but the most core uses of lexical items. It is suggested that exercises of a problem-solving nature will help learners to unearth these pervasive metaphors in idiomatic language; some exercises are presented. (LLBA 1999, vol. 33, n. 4)