The problem is easy to solve.为什么用to solve

问题描述:

The problem is easy to solve.为什么用to solve
The problem is easy (to solve).
这句话里用的是to solve,为什么不能用to be solved或者直接用solved?

这是个固定句型主语+ be+ 形容词+ to do(主动式,因为句子的主语是不定式的逻辑宾语)再如:The question is easy to answerThe sentence is difficult to translate.The apple is good to eat.The math problem is e...可是问题不是被解决吗,不就应该用to be solved吗,solved也可以表示被动,为什么不能用啊?我说了, 此句型中的主语是不定式的逻辑宾语!!!你看:The problem is easy to solve.=It is easy to solve the problem.