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
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 toeg: 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)
