to have done怎么理解,这个是不定式的完成时,可以举例子说明吗?to do 是表将来,未完成的,have done 是已经做过的,组合在一起怎么理解?

I go out to have my hair cut. 这个答案行不行

英语中to have done 表示发生在谓语动词之前的动作
eg . He seemed to have seen the film .
He is said to have gone abroad to study .

to have done 是不定式的完成结构 表示这个动作发生在谓语动作之前 所以要用完成结构
He is said to have lost his car.比如这个句子的谓语动词的 is said 但是 lose his car 这一动作发生在谓语动词 said 之前 所以非谓语要用 完成式