什么时候用不定式的主动形式表被动意思.请顺便举几个例子.

1.通常不定式的逻辑主语是动作的承受者是，要用被动态 eg：i am proud to be chosen. 2.有些场合即可用主动态也可用被动态，意义没区别 these boxes are not strong enough to use/to be used as a platform. 但有时there be结构中两者有区别： there was nothing to see=there was nothing for one to see. there was nothing to be seen=the thing being looked for was not there. 3.下列场合习惯用主动态表被动意义： this house is to let(招租) you are not to blame for what happened.(这属于blame特殊用法) a lot remains to do. 4.再有就是刚刚的例子something to eat/to say 可以理解为做后置定语或者宾语补语。 我知道的就这么多，希望对你有帮助。