We change regular verbs to the simple past and past participle forms by adding “-ed” (or “-d” if the verb already ends in “e”). For example, “talk” becomes “talked” and “dance” becomes “danced.”
Some regular verbs change their spelling in other ways, such as doubling the final letter or replacing “-y” with “-ied,” but they still follow predictable patterns. Regular verbs are always the same in their past and past participle forms.
Irregular verbs don’t follow the regular rule of adding “-ed” or “-d” to form the simple past and the past participle forms. They can change in a variety of ways or not change at all, and their simple past and past participle forms can be (but aren’t always) different.
For example, “go” becomes “went” in the simple past but is “gone” as a past participle, while “hit” is the same in all three forms.