if I hadn't/didn't

English as a Second Language English Vocabulary, Grammar and Idioms
1

  1. But the bike was probably from 2011 and you have still saved some money (I paid less),so the serial number could be different, but I would have to check it at home if I hadn’t returned the printed booklet to the store (in the past).

  2. But the bike was probably from 2011 and you have still saved some money (I paid less),so the serial number could be different, but I would have to check it at home if I didn’t return the printed booklet to the store (in the past).

which one is correct and why?

thank you very much

2

Neither looks right to me in combination with “would have to”. Do you mean that you would check the serial number at home if you could, but you can’t because you have returned the booklet in which the serial number was listed? If so, you can say:

“I’d check it at home if I hadn’t returned the printed booklet to the store”.
“I’d check it at home, but I’ve returned the printed booklet to the store”.

However, these do not seem to work when connected to the rest of the sentence with “but” . The relevant contrast is not present. This would work:

“… the serial number could be different, but I can’t check it because I’ve returned the booklet to the store”.

I also do not understand how “so” works in this sentence. It may be the wrong word.

3

Thank you Dozy. You are irreplaceable…
Do you mean that you would check the serial number at home if you could, but you can’t because you have returned the booklet in which the serial number was listed?- YES
Why can’t I say ‘‘I would have to check’’ instead of ‘‘I would check’’?

4

“I would have to check” normally implies that it is possible for you to check.

5

yes, it is. so why can’t I say that?

6

I understood from your previous reply that it isn’t possible for you to check because you no longer have the booklet.

7

the new knowledge for me. many thanks.