Hi people!

Is this sentence correct?

"The auxiliary should be in the same tense as the action we are comparing".

When do we use the same that and when the same as?

E.g: He is the same age as his wife.

       I bought the same car as yours.

       I bought the same car that you did.

Is it that when a noun (or pronoun) follows, we use "as", and when a clause follows we use "that"? In my example, the noun "action" is postmodified by the clause "we are comparing", but we should take the construction after "as" as a noun "the action we are comparing", and not as a clause, shouldn't we?

Thanks a lot!

Regards,

Mara.