Past participle

Regular verbs

Add -ed to turn a regular verb into a past participle.
As with the past simple, the -y sometimes changes to an -ie and the last consonant is sometimes doubled.

Examples

Present tense	Past tense	Past participle
to play	played	played
to live	lived	lived
to own	owned	owned
to work	worked	worked
to cry	cried	cried
to prefer	preferred	preferred

Irregular verbs

The irregular verbs have their own form that you have to memorize/study.

Examples

Present tense	Past tense	Past participle
to be	was/were	been
to build	built	built
to buy	bought	bought
to come	came	come
to do	did	done
to drink	drank	drunk
to drive	drove	driven
to eat	ate	eaten
to feel	felt	felt
to find	found	found
to get	got	got
to give	gave	given
to go	went	gone
to know	knew	known
to leave	left	left
to make	made	made
to meet	met	met
to read	read	read
to say	said	said
to see	saw	seen
to sit	sat	sat
to sleep	slept	slept
to take	took	taken
to teach	taught	taught
to tell	told	told
to think	thought	thought
to understand	understood	understood
to wear	wore	worn
to write	wrote	written

You can find various lists of irregular verbs on the internet.