Irregular verbs are verbs that do not follow the regular -ed pattern for the past tense and past participle. Instead, they change in their own ways, such as vowel changes, different endings, or no change at all. Learning them means knowing their principal parts and using the correct form in the correct tense or structure.

To use an irregular verb accurately, focus on three forms: the base form, the past tense, and the past participle. The past tense is used for finished past actions, while the past participle is used with helping verbs in perfect tenses and in the passive voice. Many errors come from mixing up the past tense and the past participle.

Word/Phrase	Definition	Example
Base form	The dictionary form used for present tense and after do or will	I go every day.
Past tense	The simple past form for finished past time	I went yesterday.
Past participle	The form used with have or be in perfect and passive structures	I have gone already.

Use the irregular past tense to talk about completed actions or events at a specific time in the past. This form stands alone without have, and it often appears with past time markers like yesterday, last week, or in 2020. Do not use the past participle by itself as the main verb in the simple past.

Perfect tenses use have plus the past participle, not the past tense. Present perfect connects past actions to the present, past perfect shows an earlier past action, and future perfect shows completion before a future time. The helping verb changes, but the main verb stays as the past participle.

The passive voice uses be plus the past participle to focus on the receiver of an action. The tense is shown by the form of be, while the main verb stays in the past participle. This is a common place where irregular past participles are required.

Many irregular verbs follow recognizable change patterns that help you group and remember them. Some change vowels, some change endings, and some have the same form for two or even all three key parts. Patterns help prediction, but each verb still needs confirmation of its forms.

Rule	Example
Vowel change base to past to participle	sing → sang → sung
Same past and participle	buy → bought → bought
All three forms the same	cut → cut → cut
Past equals base, participle differs	come → came → come
Mixed change with different consonants	think → thought → thought

Some irregular verbs do not change in the past tense or past participle. These verbs rely heavily on context and time words, because the verb form looks the same across tenses. Be careful to still mark tense correctly through auxiliaries, especially in perfect tenses and passives.

Irregular forms appear within broader sentence structures that signal time and grammar. Do-support uses the base form, modal verbs take the base form, and perfect or passive structures force the past participle. Tracking the auxiliary verb is often the fastest way to choose the correct irregular form.

Rule	Example
After did, use the base form	Did you go?
After modals, use the base form	She can go tomorrow.
After have, use the past participle	They have gone home.
After be in passive, use the past participle	It was written quickly.

Some irregular verbs include spelling changes that affect the past or past participle forms. These changes are not random: they often reflect older patterns in English. Because spelling is part of accuracy, learn the exact written form alongside pronunciation.

A small group of irregular verbs appears very often in everyday English, so mastering them gives a large improvement in fluency and accuracy. These include be, have, do, go, get, make, take, come, see, and give. Prioritize the verbs you use most in speaking and writing, and memorize their three key forms.