he'd
pron. A2 Elementary hed
pron. a short way of saying 'he had' or 'he would'.
pron. a contraction representing the subject pronoun 'he' combined with the auxiliary verbs 'had' or 'would'.
He'd already finished his dinner when I arrived.
If he knew the truth about the surprise party, he'd probably be very excited.
He'd been working at the firm for over a decade before he finally decided that he'd like to pursue a career in the arts instead.
Usage
The meaning depends on the following verb: followed by a past participle, it means 'he had'; followed by an infinitive, it means 'he would'.
Pitfall
He'd went to the store.He'd gone to the store.When 'he'd' means 'he had', it must be followed by the past participle (gone), not the simple past (went).