ㅂ-irregularity

In Korean morphology, a ㅂ-irregular verb (ko: ㅂ 불규칙 동사) is a type of irregular verb whose stem ends in ㅂ.

Inflection

After appending a suffix as you would with any other verb, check if ㅂ is followed by a vowel; if so, the stem should mutate according to the following rules:

• Add the suffix as usual.

• If ㅂ is preceded by ㅗ and followed by the infinitive -어,Or any of 어's derivatives like -었더. change ㅂ to 오.

• Otherwise, change ㅂ to 우.

It is important to append the suffix as usual before considering irregularity rules to get correct results, particularly when it comes to suffixes beginning with an optional vowel.

As a rule of thumb, ㅂ-irregularity is often applied to adjectives and rarely applied to verbs.Per HowToStudyKorean. can't cite because no zotero on my laptop lol.

Examples

Below are a few examples of ㅂ-irregular verbs:See also: Wiktionary's lists of ㅂ-irregular adjectives and verbs.

돕다

to help

• present tense: 도와요

• past tense: 도왔어요

• future tense: 도울Why 도울 and not 도올 or 돌? This is a consequence of considering irregularity rules after appending the suffix. 거예요

어렵다

to be difficult

• present tense: 어려워요

• past tense: 어려웠어요.

• future tense: 어려울 거예요.

춥다

to be cold

• present tense: 추워요

• past tense: 추웠어요

• future tense: 추울 거예요