-으면

V/Adj/이다,아니다 + (으)면 This indicates the conditions and assumption. (if)

돈을 벌면 집을 살 거예요.

If I make money, I will buy a house

운이 좋으면 시험에 합격할 거예요.

If I'm lucky, I will pass the exam

제가 대통령이면, 전쟁을 멈출 거예요.

If I were president, I would stop the war.

날씨가 좋았으면 오늘 소풍을 갔을 거예요.

If the weather had been good, I would have gone on a picnic today.

→ "날씨가 좋으면 소풍을 갈 거예요.(If the weather is good, I will go on a picnic)" expresses a simple hypothesis about the future. However, when -으면 is used with past tense(-았/었으면), it creates a hypothetical situation contrary to reality, conveying either hope or regret about what actually happened. For example, the example sentence above implies that the weather is not good right now, conveying the speaker's disappointment about the situation.

• -으면 좋겠다 : Habitual expressions to deliver a speaker’s hopes. (It would be nice if~, I wish)

로또에 당첨되면 좋겠어요. I hope I win the lottery.

김치가 더 매우면 좋겠어요. I wish the kimchi was spicier.

• - 으면 안 되다: You are not allowed to(can’t)~, You shoulnd’t.

지금 화장실을 가면 안 돼요. You can't go to the bathroom right now.

여기에서 전화하면 안 돼요. You are not allowed to make phone calls here.

• Tense: There are no strict tense restrictions.