Forms of the Verbs
The basic forms of the verb in Modern English are: the Infinitive, the Past Indefinite, and Participle II. According to the way in which the Past Indefinite and Participle II are formed, verbs are divided into three groups: regular verbs, irregular verbs, and mixed verbs. Regular Verbs Regular verbs form the Past Indefinite and Participle II by adding - ed to the stem of the verb, or only - d if the stem of the verb ends in - e. to want — wanted to open — opened to unite — united to live — [...]
Irregular Verbs Exercise
Test your knowledge of Irregular Verbs
Irregular Verbs – Complete List
Any verb that does not add -ed or -d to its past tense form is considered an irregular verb. The word 'irregular makes it sound like these verbs are rare, but you see them all the time in writing and in conversation.