Ten common irregular verbs form their past tense in the same way. Bring, buy, fight, find, grind, seek, think, and wind take ou (brought, bought, found), while catch and teach take au (caught, taught). The vowel of the verb tells you which one to use.
When you learn English, or any other language, you come across many tricky parts. Don't give up: learn some tricks, rules, and patterns, and learn the rest by heart. Irregular verbs are one of the things many learners of English struggle with, and they can be a real hassle.
Is it you are or you is? Why is it I ate and not I eated?
Unfortunately, some of these forms simply have to be learned by heart. There is no way around remembering the forms of to be, or the past tense of to cut, to cost, and to hit, which is the same as the present: cut, cost, hit. But you do not have to learn every irregular verb until you can recite it in your sleep. Some follow patterns that are easy to remember.
Catch and caught, bring and brought
This article looks at ten irregular verbs that look different but form their past tense in a similar way: bring, buy, catch, fight, find, grind, seek, teach, think, and wind (as in winding a clock).
Verbs with i, u, or e: the past tense has ou
First, the verbs with an i, u, or e. From the list above, these are bring, buy, fight, find, grind, seek, think, and wind. They all have one thing in common: their past tense and their past participle are spelled with ou.
| Verb | Past tense | Past participle |
|---|---|---|
| to bring | brought | brought |
| to buy | bought | bought |
| to fight | fought | fought |
| to find | found | found |
| to grind | ground | ground |
| to seek | sought | sought |
| to think | thought | thought |
| to wind | wound | wound |
Most of them end in -ought; find, grind, and wind end in -ound.
Verbs with a or ea: the past tense has au
The only verbs from the list with an a or ea are catch and teach. Their past forms are spelled with au:
| Verb | Past tense | Past participle |
|---|---|---|
| to catch | caught | caught |
| to teach | taught | taught |
A memory aid, not a law
This simple rule is a memory aid, not a linguistic explanation, and it only works for the verbs in this list. Not every verb with an i follows it: drink becomes drank, and sing becomes sang.
From a linguistic point of view, these past forms are a case of allomorphy, more precisely of weak suppletion: they are built from similar variants of the verb, but no sound rule decides which verb takes which variant.
For more verbs that do not follow the usual -ed rule, see irregular verbs in English, and for a famously confusing pair, lie vs. lie and the past tense.