1、use可以作动词和名词
(1) 作动词时，“使用，利用，服用（毒品）”
过去式used，过去分词used，现在分词using.
(2) 作名词时，“使用，使用权，功能”
形容词useful , 副词usefully
2、关于use 的三个固定句型：
(1) used to do sth. "过去常常做某事"
(2) be used to do sth. "被用来做某事"
(3) be used to doing sth "习惯做某事"
3、辨析：
(1)used to do sth. "过去常常做某事"
to 后加动词原形,否定句为didn't use to或used not to
eg: I used to take a walk after supper every night.
(我过去常常在每天晚上饭后去散步)
(2) be used to do sth. "被用来做某事"
to 后加动词原形
eg: Wood is used to make paper.
(木材被用来造纸)
(3) be used to doing sth "习惯做某事"
to是介词，后加名词，动名词或代词
eg: He is used to getting up early.
(他习惯早起)