못: Can't

못: "can't", and why it isn't 안 an

못 is the particle of things getting in your way. Korean splits negation into two words where English only has one, and the split is about why the thing isn't happening.

안 an is choice, 못 is obstacle

• 술을 안 마셔요. sur-eul an masyeoyo — "I don't drink." A decision.
• 술을 못 마셔요. sur-eul mot masyeoyo — "I can't drink." Something stops you: an allergy, medication, a low tolerance.

English says "I don't drink" for both and lets tone carry the rest. Korean makes you pick, and picking wrong changes what you told someone about yourself.

Where it goes

• Short form: 못 in front of the verb. 못 가요 mot gayo, "I can't go."
• Long form: verb stem + 지 못하다 ji motada. 가지 못해요 gaji motaeyo. More formal, more common in writing.

The 하다 trap. With 하다 verbs, 못 slips inside the word rather than sitting in front of it:

• 공부 못 해요. gongbu mot haeyo ✓ — "I can't study."
• 못 공부해요 mot gongbuhaeyo. ✗

The noun comes first, then 못, then 해요 haeyo. This one catches nearly everyone at least once.

It doesn't work with adjectives

못 is about ability, and adjectives don't describe abilities. So:

• 못 예뻐요 mot yeppeoyo ✗

If you want "not pretty", you need 안 예뻐요 an yeppeoyo or 예쁘지 않아요 yeppeuji anayo. Reaching for 못 here is a reliable sign someone learned the word as "not" rather than as "can't".

How it actually sounds

못 is written with a ㅅ 받침 batchim but pronounced [몯 mot], and it assimilates hard against whatever follows. This is why you can know the word and still not catch it in speech.

• 못 해요 mot haeyo → sounds like [모태요 motaeyo]
• 못 먹어요 mot meogeoyo → sounds like [몬머거요 monmeogeoyo] monmeogeoyo
• 못 가요 mot gayo → sounds like [몯까요 motkkayo] motkkayo

If you've been hearing 몬 mon and 모 mo in dramas and wondering what word that was, this is it.

못 vs 지 못하다 ji motada vs 없다

Three ways to say something can't happen, and they aren't interchangeable:

• 못 마셔요 mot masyeoyo — I'm unable to drink.
• 마시지 못해요 masiji motaeyo — same thing, more formal.
• 마실 수 없어요 masil su eopseoyo — there's no possibility of drinking. Often circumstantial rather than personal.

The ~(으)ㄹ 수 있다 (*su itda*)/없다 page covers that third one properly.

못하다: "bad at", and 잘못하다

Written as one word, 못하다 motada often means "to be bad at" rather than "can't". Adding 잘 jal makes it gentler, and the spacing matters:

• 요리를 못해요. yorireul motaeyo "I'm bad at cooking."
• 요리를 잘 못해요. yorireul jal motaeyo "I'm not very good at cooking." The polite, modest way to say it.
• 제가 잘못했어요. jega jalmotaesseoyo "It was my fault." With no space, 잘못하다 jalmotada means "to do wrong".

So 잘 못했어요 jal motaesseoyo is "I didn't do it well", but 잘못했어요 jalmotaesseoyo is an apology.

못 + 겠다: "I just can't"

못 mot with 겠어요 gesseoyo is how you say you've hit your limit. It's very common when you're tired, full or fed up:

• 더는 못 참겠어요. deoneun mot chamgesseoyo "I can't take it anymore."
• 배불러서 더 못 먹겠어. baebulleoseo deo mot meokgesseo "I'm full, I can't eat another bite."