English Grammar 101 - Verbs: Types, Tenses, and Moods, Lesson 7: Irregular Verbs (2024)

Irregular Past Tense and Past Participles

Here are a few basics you'll want to remember about the irregular past tense and past participle forms.

• They all have one important characteristic in common: they almost never end in -ed. Some examples are ate, fought, swam, and given.
• It's very common for a vowel (or pair of vowels) to be different from the base form. Began (base form, begin) and froze (base form, freeze) are a two good examples.
• Most irregular verbs follow a specific pattern. You'll learn more about this concept later in this lesson.

Let's take a closer look at how the irregular past tense and past participles are formed.

Past Tense

With the irregular past tense, it is common for a vowel in the middle of the verb to change instead of the verb's ending. The verb drive, for example, changes to drove in the past tense.

Other verbs require you to change a vowel and add a new ending. Eat, for example, turns into ate in the past tense.

One of the most common irregular past tense endings is -t (sweep → swept). Sometimes you'll add -d (sell → sold) or -ght (catch → caught) instead.

Often, when the base ends in -ck, -e, -g, -ght, or -n, the past tense will keep that final letter or set of letters.

stick → stuck
drive → drove
ring → rang
fight → fought
run → ran

Past Participles

Just like the irregular past tense, irregular past participles can be formed by changing a vowel, adding a new ending, or doing both. However, the vowel or ending is often (but not always) different from the past tense form. For example, many irregular past participles require you to add an -en, -n, or -ne ending (drive → driven).

Many irregular past participles end in -en, but, similarly to the past tense, they can also end in -t, -ck, -d, -e, -g, or -ght.

In the table below you'll find several examples of how the irregular past tense and past participles are formed. Pay special attention to the vowel changes and different endings.

*For some verbs, such as sleep, freeze, and eat, a pair of vowels changes instead of just a single vowel.

Irregular Verb Patterns

Now that you have an idea of how to form the irregular past tense and irregular past participles, let's take a look at some patterns that an irregular verb may follow.

Common Patterns

• Sometimes the past tense and past participle are the same. All the verbs in this category have at least one of the following characteristics:

  • The most common past tense and past participle endings you will add to these verbs are -t, -ght, and -d (sweep/swept/swept; catch/caught/caught; sell/sold/sold).
  • You will never add an -en, -n, or -ne ending to these verbs. The only time the past forms end in -n or -ne is when that ending is already part of the base form (shine/shone/shone).
  • Sometimes the base, past, and past participle endings are all the same. This happens most often when the base ends in -ck, -g, -ght, or -ne.

  You'll want to keep these characteristics in mind as you study irregular verbs, but don't worry about memorizing them all. Use the table below to help you start recognizing all the patterns.

  Base	Past	Past Participle
  sweep	swept	swept
  catch	caught	caught
  sell	sold	sold
  shine	shone	shone
  swing	swung	swung
  fight	fought	fought
  stick	stuck	stuck

• It is common to form the past participle by adding -en, -n, or -ne to the end of the base or past tense form.

  Base	Past	Past Participle
  eat	ate	eaten
  give	gave	given
  do	did	done
  freeze	froze	frozen

• For some verbs, the base, past tense, and past participle are all the same. The base form of these verbs almost always ends in -t (a couple of them end in -d, but that's very unusual).

  Base	Past	Past Participle
  put	put	put
  set	set	set

  Keep in mind that this pattern does not apply to all verbs ending in the letter -t—there are quite a few, such as connect, visit, and lift, that are regular verbs. Also, verbs with a base form ending in -ght never follow this pattern.

• Sometimes, the final vowel changes from i in the base to a in the past, and then to u in the past participle.

  Base	Past	Past Participle
  begin	began	begun
  ring	rang	rung

Rare Patterns and Stand-Alone Irregulars

• With the verbs run, come, become, and overcome, the base and past participle are the same. These are the only four verbs that follow this pattern, so keep an eye out for them—people often make the mistake of thinking that the past tense and past participle forms are the same.

  Base	Past	Past Participle
  run	ran	run
  come	came	come

• The base, past tense, and past participle are all completely different. This doesn't happen very often. The verb fly is a good a example.

  Base	Past	Past Participle
  fly	flew	flown

• With the verb beat - and only the verb beat - the base and the past tense are the same, but the past participle is different.

  Base	Past	Past Participle
  beat	beat	beaten

  Keep in mind that any other verb that has the same base and past tense will also have the same exact past participle (for example, put/put/put).

Present Tense: Irregular Third Person Singular

Verbs that are irregular in the present tense are almost always irregular only in the third person singular form (he, she, it). There are very few verbs that fall into this category; they are to have, to do, and to go. These verbs also have an irregular past tense and past participle.

Hint:

There are certain verbs that have do, go, or have as their root.¹ These verbs will have the same irregular forms as the root verb.

The verb forgo, which has the root go, has an irregular past tense form and past participle (forwent, forgone).

The verb undo, which has the root do, is irregular in the third person singular form of the present tense and has an irregular past tense and past participle (undoes, undid, undone).

The Verb To Be

The verb to be is the most irregular verb in the English language. It is irregular in all forms of the present and past tenses, and it has an irregular past participle.

Try it out:

Fill in each column with the correct form of the given verb. Then check your work. Practice the ones you miss.

1. A root is the most basic part of a word. Sometimes a root is a stand-alone word, and sometimes it's just part of a word. You can combine the root with other elements to make new words. Elements you add to the beginning of a word are called prefixes, and elements you add to the end of a word are called suffixes.

   for + go = forgo
   under + go = undergo
   re + do = redo
   un + do = undo

   The roots in the examples above are go and do. The other elements are all prefixes.