I've never been a great one for writing letters.

　　我向來不喜歡寫信。

　　She hasn't written ─ not that she said she would.

　　她還沒寫信來——倒不是她說過她要寫。

　　This expression is used mainly in speech, not in writing.

　　這種表達主要用于口語，而不是書面語。

　　Get everything in writing in order to cover your back.

　　一切都要立字為據，以絕后患。

　　He told us not to write more than three sides.

　　他告訴我們寫字不要超過三面紙。