Fact. Use this word only of matters of a kind capable of direct verification, not of matters of judgment. That a particular event happened on a given date, that lead melts at a certain temperature, are facts. But such conclusions as that Napoleon was the greatest of modern generals, or that the climate of California is delightful, however incontestable they may be, are not properly facts.

On the formula the fact that, see under [Rule 13].

Factor. A hackneyed word; the expressions of which it forms part can usually be replaced by something more direct and idiomatic.

His superior training was the great factor in his winning the match.He won the match by being better trained.
Heavy artillery has become an increasingly important factor in deciding battles.Heavy artillery has played a constantly larger part in deciding battles.

Feature. Another hackneyed word; like factor it usually adds nothing to the sentence in which it occurs.

A feature of the entertainment especially worthy of mention was the singing of Miss A.(Better use the same number of words to tell what Miss A. sang, or if the programme has already been given, to tell how she sang.)

As a verb, in the advertising sense of offer as a special attraction, to be avoided.

Fix. Colloquial in America for arrange, prepare, mend. In writing restrict it to its literary senses, fasten, make firm or immovable, etc.

Get. The colloquial have got for have should not be used in writing. The preferable form of the participle is got.