Except. Do not use except for unless. See §85.

Wrong: I can not sleep except it is quiet.

Expect. Do not use expect in the sense of suppose or think.

Wrong: I expect you have read that book.
Right: I suppose you have read that book.

Fine. Do not use fine in place of some more definite word. Fine is a much over-worked word.

Wrong: The book is fine for class-room work.
Right: The book is well adapted for class-room work.

Firstly. Firstly should never be used. Say first. See §40.

First-rate. Do not use first-rate as an adverb in the sense of very well.

Wrong: That does first-rate.
Right: That does very well.
Right: He is a first-rate fellow.

Former. Do not use former when more than two are referred to. Say first. See §41.