I find it difficult to finish it.和I find it isdifficult to f

I find it difficult to finish it.和I find it isdifficult to finish it 句子意思没有区别,但是前句的difficult 作宾语补足语.后句it isdifficult to finish it.是一个宾语从句.
She says _____not right to do that.这个必须是it is .因为 says 后不能跟（宾语+宾补）.而find 则可以说find sth adj