Regular verbs follow a consistent pattern when forming past tense and past participle forms, while irregular verbs do not follow standard conjugation rules.
Regular verbs add -ed to the base form to create both the past tense and past participle. Examples include: walk (walked), play (played), and listen (listened). This pattern applies to the vast majority of English verbs, making them predictable and easy to learn.
Irregular verbs change their form unpredictably when conjugating. Some common examples are: go (went, gone), eat (ate, eaten), see (saw, seen), and be (was/were, been). These verbs often undergo vowel changes, use entirely different words, or follow no discernible pattern.
The distinction matters because regular verbs can be conjugated by simply applying the -ed rule, while irregular verbs must be memorized individually. English has roughly 200 commonly used irregular verbs, though many are among the most frequently used words in the language—such as "be," "have," "do," and "go."
Historically, irregular verbs tend to be older, more fundamental words that were used so frequently that they resisted regularization over time. Newer or less common verbs typically follow the regular pattern, which is why the regular conjugation is considered the "default" rule in English. Understanding this distinction helps learners know when to apply the standard rule and when to rely on memorization instead.