Irregular ㅂ
For a few verb and adjective stems that end in ㅂ, ㅂ changes to 오 or 우 when added to an ending that begins with a vowel. 돕다 (to assist) and 곱다 (lovely/charming) are the only two words that change to 오, while all others change to 우.
For a few verb and adjective stems that end in ㅂ, ㅂ changes to 오 or 우 when added to an ending that begins with a vowel. 돕다 (to assist) and 곱다 (lovely/charming) are the only two words that change to 오, while all others change to 우.
Although the stems of 좁다 (to be narrow), 입다 (to wear), 씹다 (to chew), and 잡다 (to catch) end in ㅂ, they are conjugated regularly.
When the verb is 돕다 or 곱다, ㅂ is replaced by 오.
Otherwise, ㅂ is replaced by 우.