Comment by thaumasiotes

Those occur when you've made an unambiguous statement that has no valid semantics. ("God should get a promotion."†) They don't occur when you've made an ambiguous statement ("We saw her duck.") As I noted above, it isn't possible to make an ambiguous statement.

† I'm aware that that isn't an unambiguous statement. This is for the simple reason that it's next to impossible to make an unambiguous statement in a natural language; that's why legal documents use so many clauses. I'm relying on the reader here to realize which meaning I had in mind, which is the way all natural language works.