§23

Wittgenstein says that there are indefinitely many kinds of words, signs, and sentences. New kinds might come into existence and old ones might become obsolete. You could also add the point made in §17 here - that words can be classified in a variety of ways depending on the aims of classification.

Wittgenstein says that it is worth thinking about what logicians have said about language in this light. - Presumably his point is that 'logicians'/philosophers of language have thought about language in abstraction from the activities that speaking a language is part of and that this has distorted their view of language.