英语中,什么情况下动词不定式主动表被动

某些动词的主动形式可以表示被动意义,如： A) 某些感官动词和系动词加形容词可以表示被动意义,如look, smell, taste, feel, prove, wear, sound等. The flower smells sweet. The music sounds dulcet. B) 某些及物动词后加副词,也可以表示被动意义,如cut, clean, draw, lock, open, pack, play, peel, sell, shut, split, strike, record, iron, keep等. This type of TV sells well. The meat cuts easily. 比较： The door doesn't lock.这个门锁不上.（门本身的性质） The door was not locked.这个门没有上锁.（门当时的状态） The window opened. 窗户开了.（强调窗户自身开了.） The window was opened. 窗户被打开了.（强调被人打开了） C) deserve, need, require, repay, stand, take, want等词的后面可以用动名词的主动形式表示被动意义.若动名词是不及物的,后面应跟有介词. This question deserves mentioning. The coat requires washing. The kids need taking care of. The table wants cleaning. D) 某些作表语的形容词后,用不定式主动形式表示被动意义. The stone is hard to break. It is easy to understand. The meat is not fit to eat. The book is difficult to read.