Because (Reason)

Use -아/어서 to express cause or reason: Conjugation (same as present tense): • ㅏ/ㅗ stems + 아서: 가다 → 가서 • Other stems + 어서: 먹다 → 먹어서 • 하다 → 해서 Meaning: "because" / "so" / "and then" • 배가 고파서 밥을 먹었어요 = I ate because I was hungry • 늦어서 죄송합니다 = I'm sorry for being late Important rules: • Cannot use imperative/suggestion after -아/어서 ✗ 늦어서 빨리 오세요 (wrong) ○ 늦으니까 빨리 오세요 (correct - use -니까) • First clause is often the reason, second is the result • Tense only on final verb: 피곤해서 집에 갔어요