Would people *please* try to do their homework on their own! It doesn't take much to look on Google for, say, 'english verbs'. I did, and got a huge list of irregular english verb forms - have a look at http://tinyurl.com/6jxey
Drank is the past (perfect) tense: drunk is the past participle and (he was) drinking is the imperfect tense. (And ask another question is you want to know what all the tenses are!)