As linguists have often pointed out, there are paradoxes involved in
correcting or teaching informal language. They would argue that everyone
has competence in the informal conversational varieties of their native
language: this is simply what is meant by being a native speaker of a
language. And I have already mentioned some arguments against teaching
foreign learners productive competence in informal spoken varieties of
language. Much of this section may therefore seem rather negative or to
shade into something else, namely teaching written language. However,
some of the confusions involved are rife in much educational research, and
current work in the forms and functions of written and spoken discourse can
make explicit some of these confusions.