help me"in which gramatic rule"(have had) with 1st n 2nd person(has had)used with 3rd person collectivly

Question

tell me i m to much confused because has have used in present perfect tense n had used in past perfect tense
but tell me abut the(has had) (have had) n also clear the verb which degree should be used
n i read in my graduate text book but i can't understand the correct usage of it any one know tell me clearly plz

Answer 1

You need two independent clauses: You and I have had a good time, but he has had the worst time of his life. The rule is simple: only one verb can be conjugated per subject/predicate. Each "to have" indicates the present perfect.
X: You, he and I have and has had a good time. wrong