German Grammar Explained /

Strong Verbs: Class 3

This is a follow up of "Strong Verbs: Class 2", where we said:
There are groups of verbs that although they are irregular, each group follows the same pattern! :)
So far:
Class 1: ei → ie (bleiben → geblieben) Class 2: ie → o (fliegen → geflogen)
Strong Verbs: CLASS 3
i
u
finden
gefunden
singen
gesungen
springen
gesprungen
trinken
getrunken