Condition -(으)면 (if / when)

What it means

-(으)면 means "if" or "when". The first part is the condition, and the second part is what happens when that condition is true. English puts "if" at the start of the clause, but Korean puts -(으)면 at the end of it: 시간이 있으면 = "if (I) have time".

How to make it

• Stem ends in a vowel → add 면: 가다 → 가면, 보다 → 보면
• Stem ends in ㄹ → just add 면: 살다 → 살면, 만들다 → 만들면
• Other consonants → add 으면: 먹다 → 먹으면, 읽다 → 읽으면, 있다 → 있으면
• Nouns → 이면 after a consonant, 면 after a vowel: 학생 → 학생이면, 의사 → 의사면. (이)라면 is also used, especially for "if it were...": 나라면 (if I were you)
• Past form -았/었으면 → for imagined situations and wishes: 돈이 많았으면 좋겠어요 (I wish I had a lot of money)

When to use it

• Real conditions: 시간이 있으면 같이 영화 봐요. (If you have time, let's watch a movie together.)
• Results and advice: 이 약을 먹으면 괜찮아질 거예요. (If you take this medicine, you'll get better.)
• Things that always happen: 겨울이 되면 눈이 많이 와요. (When winter comes, it snows a lot.)
• General situations: 서울에 살면 지하철을 자주 타요. (If you live in Seoul, you often take the subway.)

Compare

• -(으)면 = a condition, "if / whenever": 봄이 되면 꽃이 펴요. (When spring comes, flowers bloom.)
• -(으)ㄹ 때 = a moment in time, "at the time when": 한국에 갈 때 비행기를 탔어요. (When I went to Korea, I took a plane.)
• For one specific moment in the past, use -(으)ㄹ 때 (어렸을 때 = when I was young), not -(으)면.

Common mistakes

• ❌ 살으면 → ✅ 살면 (ㄹ stems take only 면)
• ❌ 먹면 → ✅ 먹으면 (a consonant stem needs 으)
• ❌ 어렸으면 자주 울었어요 → ✅ 어렸을 때 자주 울었어요 (a past moment, not a condition)