Present perfect and simple past in same sentence "have" and "had" [closed]

I have seen the other questions similar to this topic, but they all explain how the sentence is in present perfect and simple past. My question is, I would like to know why, or what the grammatical reason the use of both the words 'have' and 'had' is correct for the same subject ('it' is the subject here):

"Not only did it have XYZ, it also had ABC."

Note, ABC and XYZ can be swapped and both ABC and XYZ hold true all the time eg, "not only did it have cruise control/automatic windows, it also had automatic windows/cruise control".

What are the grammatical rules allowing this? Note I am not saying it is breaking any rules, rather, I'm asking why don't we say "have" twice, or "had" twice. Thanks

Solution 1:

There is no rule that says you can't have the present tense and past tense in the same sentence.

In any case, your sentence contains no present tense verb. Both verbs are in the past tense. When the phrase not only introduces a clause it requires inversion of the subject and the verb as well as the addition of an auxiliary. It is the auxiliary which indicates the tense. The auxiliary here is did, which is the past tense.

The Collins Cobuild English Usage (p442) has this entry on not only:

For emphasis, you can put not only first, followed by an auxiliary or 'be', then the subject, then the main verb.

• Not only did they send home substantial earnings, but they also saved money.
• Not only do they go rarely go on school outings, they rarely, if ever, leave Brooklyn.