Regular and Irregular Verbs
The distinction between regular verbs and irregular verbs is a very simple one:
Those verbs that form their past participle with ‘d’ or ‘ed’ are regular verbs. These verbs do not undergo substantial changes while changing forms between tenses.
1. If the verb ends with a vowel, only ‘d’ is added. For example:
2. If the verb ends with a consonant, ‘ed’ is added. For example:
Those verbs that undergo substantial changes when changing forms between tenses are irregular verbs. The changed forms of these verbs are often unrecognizably different from the originals. For example:
There is no way to tell what form an irregular verb is going to take in a changed tense; the only option for an English speaker is to commit the changes to memory. With practice, it will become a matter of habit.