I found this sentence:
She asked if I'd had a good time on my holiday
I'm not sure if
'd is the short form of would or of had.
Is there any criteria (for an English language learner) to understand the correct meaning of
"I'd" is used an abbreviation for both "I had" and "I would".
Which it is short for can be inferred from context.
If it is followed by a past participle, it stands for "I had":
- I'd seen him before
- I'd gone to the shops.
Otherwise, it stands for "I would":
- I'd rather go anywhere else
- I'd see him quite often
So in your sentence "I'd" can't stand for "I would", because "would" always has the basic verb form (go, see, have etc.) after it. That means it definitely has to be short of "I had".