What Does (으) Mean?
Korean grammar references often write endings with parentheses, as in -(으)면 and -(으)세요 .
The parentheses show that the ending has two forms. Choose -면 or -세요 after the vowel-final stems introduced here, and choose -으면 or -으세요 after consonant-final stems other than ㄹ.
The 으 is not an optional sound added freely for easier pronunciation. It is part of the form selected according to the stem ending. ㄹ-final stems follow a separate pattern outside this course.
Vowel-Ending Stems: Choose -면 or -세요
For the vowel-final stems introduced here, select the form without 으 : -면 or -세요 . Attach that selected form directly to the stem.
Examples
가다 → 가- + -면 → 가면
가다 → 가- + -세요 → 가세요
보다 → 보- + -면 → 보면
보다 → 보- + -세요 → 보세요
Consonant-Ending Stems: Choose -으면 or -으세요
For stems ending in a consonant other than ㄹ, select the form containing 으 : -으면 or -으세요 .
Examples
먹다 → 먹- + -으면 → 먹으면
먹다 → 먹- + -으세요 → 먹으세요
읽다 → 읽- + -으면 → 읽으면
읽다 → 읽- + -으세요 → 읽으세요
ㄹ-final stems follow a separate pattern covered outside this course.
Common Learner Mistake
A common mistake is selecting the wrong form without checking how the stem ends.
Incorrect in the pattern taught here: 먹면
Correct: 먹으면
The stem 먹- ends in a consonant other than ㄹ, so the selected form is -으면 rather than -면 . Check whether the stem ends in a vowel or a non-ㄹ consonant before choosing the form.