为什么用for sb do sth不用for sb to do sth?答:用of 的话,adj就用来形容sb的it is adj of sb to do,这里的形容词是形容人的性格特征的,如nice,kind clever,foolish,smart,都是形容人的,it is adj for sb to do就是普通的形容词,如hard,impossible,important翻译:对我们来说学习英语太难了it is+adj+for sb to do...it is+adj+of sb to do ....