Expressing Conditions with -(으)면

In Korean, when the first action or state is a condition that makes the second part possible, we connect the two ideas using -(으)면 .

Instead of stating two separate facts, -(으)면 merges them into one natural sentence. The first part sets the condition, and the second part shows the result, plan, or reaction.

Separate Sentences · Connected with -(으)면

비가 와요.

집에 있을 거예요. · 비가 오면 집에 있을 거예요.

(If it rains, I will stay home.)

시간이 있어요.

만나요. · 시간이 있으면 만나요.

(If we have time, let's meet.)

To connect the sentences, drop the final -다 from the dictionary form and look at the last block of the stem. The choice depends on whether it ends in a vowel or a consonant (patchim).

Ends in a Vowel (No Patchim)

If the stem ends in a vowel, attach -면 .

가다 → 가면 (if I go)

오다 → 오면 (if it comes)

하다 → 하면 (if I do)

Ends in a Consonant (Patchim)

If the stem ends in a consonant, attach -으면 .

먹다 → 먹으면 (if I eat)

있다 → 있으면 (if there is)

읽다 → 읽으면 (if I read)

Note: Verbs and adjectives ending in the ㄹ patchim are a special case. They act like vowel stems and simply take -면 without adding 으 (e.g., 만들다 → 만들면).

In English, there is a strict difference between "if" (an uncertain possibility) and "when" (a certain or repeated event).

In Korean, -(으)면 naturally covers both meanings depending entirely on the context. You do not need to search for a different grammar form just because an event is guaranteed to happen.

Uncertain condition (If):

내일 날씨가 좋으면 공원에 가요. (If the weather is good tomorrow, I go to the park.)