By Singular verbs, Past perfect

So it should be: Which of these words fits this rule??? I thought that when you say: It was the first time.. then you have to use "the past perfect tense" and when you say: it's the first time.. then you have to use "the present perfect tense"??? Thank you

Hi, 1. I had to help him because he is my friend. I am confused if the use of the verb "is" in the dependent clause is correct. There is a rule that if the verb in the independent clause is in its past or past perfect form, the verb in the dependent or subordinated clause should also be in its...