①某些连系动词，如smell, taste, feel, sound, prove, turn out等,可用主动形式表示被动意义。
②某些动词，如read, write, sell, wash, clean cook, open等，当其用作不及物动词，主语是无生命的名词或代词，且和well, badly,easily, smoothly等副词连用，多用来说明主语的特征、性质或所处的状态等，可用主动结构表被动。
③某些不及物动词和短语不能用于被动语态。如:
happen,take place.come about(发生) ,break out(爆发), belong to(属于)，consist of(...组成)，come into being, come into use, come true, runout, turn up.g20 up,grow up等。(sth +不及物动词短语)
④当动词need, want, require前面是物做主语时，后跟动名词作宾语，是用主动形式表被动意义，相当于不定式的被动式即：sth need/want/require doing=sth need/want/require to be done
