1、use可以作動詞和名詞
(1) 作動詞時，“使用，利用，服用（毒品）”
過去式used，過去分詞used，現在分詞using.
(2) 作名詞時，“使用，使用權，功能”
形容詞useful , 副詞usefully
2、關于use 的三個固定句型：
(1) used to do sth. "過去常常做某事"
(2) be used to do sth. "被用來做某事"
(3) be used to doing sth "習慣做某事"
3、辨析：
(1)used to do sth. "過去常常做某事"
to 后加動詞原形,否定句為didn't use to或used not to
eg: I used to take a walk after supper every night.
(我過去常常在每天晚上飯后去散步)
(2) be used to do sth. "被用來做某事"
to 后加動詞原形
eg: Wood is used to make paper.
(木材被用來造紙)
(3) be used to doing sth "習慣做某事"
to是介詞，后加名詞，動名詞或代詞
eg: He is used to getting up early.
(他習慣早起)