As English only has one recognised verb pattern, and that one pattern has the past participle and simple past being different, then by definition any verb that doesn't have them the same is irregular, and any verb that is regular has the same form in the past simple and the past participle. If you look at tables of verbs, you will see some patterns (though not perfectly consistent), that relate to the different origins of words in different languages, or similar journeys of development in the English language.
For example, some don't change between infinitive, simple past and past participle, such as bet:
I bet you can't eat that whole steak.
I bet someone they couldn't eat a whole steak last week, and now I have no money.
I have bet on some stupid things.
And there are verbs who experience a vowel shift between infinitive and simple past, and then add -n or -en to form the past participle:
You should just forget about her.
I forgot all about my exam!
I've forgotten more than you know.
How much are you going to take from me?
He took all I had and I got nothing in return.
What do you want now? You've taken everything!
What can I give you to make you go away?
I gave you all that I had, now what?
What I have been given, I have tried to use wisely.
(Note that the -en ending might be added to the past tense form or the infinitive form.)
Knowing about these other patterns can help when you come across an unfamiliar irregular verb.
Also note that this is actually the most common form of irregularity in English verbs. Really irregular verbs like to be are much less common.