With regular verbs, you normally add ed to the infinitive to use it when talking about the past,
E.g. I walked into the room.
Sometimes the verb will end –ing, (gerunds & continuous tenses),
E.g. I was walking into the room when I tripped over.
Irregular verbs are different.
Below is a list of irregular verbs, with the ‘base form/bare infinitive’ shown in the left hand column.