i found it hard _____(understand ) him为什么要填to understand

问题描述:

i found it hard _____(understand ) him为什么要填to understand

it作形式宾语
find it +形容词+to do,实际上应该是find to do+形容词 ,但是由于宾语太长,所以用泛指代词it来代替,把to do 后置.