Few would maintain that language instruction is easy. Nor can the advice of linguists always be counted on to make it any easier. Unless they are themselves experienced language teachers, the advice of linguists on language pedagogy is likely to be of no more practical value than the advice of theoretical physicists on how to teach pole vaulting. What they can offer, qua linguists, is insight into the structure of particular languages and the properties of language in general. But even when limited in this fashion, the input of linguists cannot necessarily be trusted. They quarrel with one another about the most fundamental issues, suggesting that some of them (at least) must be fundamentally wrong. It is therefore unsurprising that the impact of linguistic theory on language pedagogy has been less than miraculous and sometimes less than helpful.