Answer:
1 . I have had lunch .
2. He has had lunch .
3. I had had lunch before you came.
Explanation:
This is one of the most confused about combinations as per my experience .I would firstly tell a bit of grammar part and then clarify with real day to day usage .
THE CONFUSION IF AT ALL COMES IS BECAUSE OF TWO DIFFERENT USAGES OF WORD “HAVE” . THEY LOOK AND SOUND LIKE SAME BUT PLEASE TREAT THEM DIFFERENTLY . So let's separate them like one of them is same like “ “AM,ARE,WILL,SHALL, “ the helping or auxiliary verbs ,and the second. “have “ is just like “ drive, eat, drink, watch” the main verb “ or I prefer to call “ Action”.
1) c. and d. because they both describe when and to what extent.
2) a. and d. because these describe to what extent and how.
3) b. because it describes to what extent
4) d. because it describes when.
5)
It is the old man is attempting to catch the fish.
