I am not sure how to explain this so i'll give you an example..
I <u>would have had</u> it done before homework
In this sentence, there are 2 words that represents past. "Would" and "Had", which makes up a past perfect.
<em>Hi There!!</em>
<em>I think the best answer is </em><em>Clause</em><em>...</em>
<em>Hope This Helps!!</em>
