감사합니다 vs 고마워: Which 'Thank You' Should You Use?
10-Second Answer
Choose by relationship, not by size of the favor: 감사합니다 for strangers, staff, elders, and work; 고마워요 for friendly-but-polite relationships; 고마워 only for close friends and people younger than you. When unsure, go one level more polite — it never offends.
The Decision Table
| Who helped you? | Say | Why |
|---|---|---|
| Taxi driver, cashier, waiter | 감사합니다 | Stranger + service = formal-polite |
| Your boss, professor, elder | 감사합니다 | Hierarchy demands the formal level |
| A friendly coworker your age | 고마워요 | Close-ish, but politeness maintained |
| Your 언니/오빠/형/누나 (close) | 고마워요 or 고마워 | Depends how casual the relationship has become |
| Your best friend | 고마워 | Formal thanks here would sound like sarcasm |
| A child or much younger person | 고마워 | Casual downward is natural |
Hear the Difference
(면접 후) 시간 내주셔서 감사합니다.
sigan naejusyeoseo gamsahamnida.
(After an interview) Thank you for your time.
Formal — anything less would hurt you here.
(동료에게) 커피 고마워요!
keopi gomawoyo!
(To a coworker) Thanks for the coffee!
Warm and still respectful.
(친구에게) 와 진짜 고마워, 최고야.
wa jinjja gomawo, choegoya.
(To a friend) Seriously, thanks — you're the best.
The Principle Behind It
English scales thanks by enthusiasm (thanks → thank you so much!). Korean scales it by relationship first — the same small favor gets 감사합니다 from a stranger and 고마워 from a best friend. Register isn't decoration in Korean; it IS the grammar of the relationship.
Safety rule: overshooting politeness (감사합니다 to a friend's parent you barely know) is always fine. Undershooting (고마워 to a taxi driver) is the direction that stings.
Mini Quiz
1. A waiter refills your water. You say:
2. Your close friend helps you move apartments all day. You say:
3. You're not sure which level fits. What's the safe move?
Related Knowledge
Learn Next
What Does 죄송합니다 (Joesonghamnida) Mean?
Sorry follows the exact same ladder logic as thank you — you already know the pattern.
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Start today's study →Last updated: 2026-08-10 · Written and reviewed by a native Korean speaker.