Theorie:

Irregular Verbs
 
In English each verb has three different forms, which are needed to construct the tenses:
 
 
Base Form
Past Tense
Past Participle
listen
listened
listened
brush
brushed
brushed
 
 
As you can see in the above table, the suffix -ed is added to the base form in order to create the second and third form of regular verbs. However, many of the most frequent verbs are irregular and, therefore, need to be learned by heart. For example:
 
 
Base Form
Past Tense
Past Participle
go
went
gone
break
broke
broken
 
 
In order to learn the irregular verbs by heart, the "Table of Irregular Verbs" of the Cambridge Dictionary Online is very useful.