Tenses in a sentence

[rajeshmalladi]

Could anyone please explain me the rules for using different possible combinations of tenses in a sentence.

Eg: Can we use present perfect and past perfect in one sentence, past perfect and past progressive in one sentence, etc.

I have a TOEFL book which says the various tenses that could appear in a dependent clause if the main clause is either in present tense or in past tense.
But it doesn't say anything about the main clause containing other tenses except the present and past(eg:present perfect). Please explain.
Thank you,
Rajesh

[Pete]

Could anyone please explain me the rules for using different possible combinations of tenses in a sentence.

Eg: Can we use present perfect and past perfect in one sentence, past perfect and past progressive in one sentence, etc.

I have a TOEFL book which says the various tenses that could appear in a dependent clause if the main clause is either in present tense or in past tense.
But it doesn't say anything about the main clause containing other tenses except the present and past(eg:present perfect). Please explain.
Thank you,
Rajesh
I tried to give a partial answer to this earlier. If anyone is familiar with such a list of possible tense pairings, please jump in.

In general it doesn't help anything to repeat questions (unless it becomes clear that one has been forgotten, maybe because it is off the first screen of questions). Those of us who try to answer questions try to answer all of them, but we can't predict how long it may take to do it. Multiple copies of the same question just delay the whole process.

Thanks for your patience.