Korean "Can" and "Can't": -(으)ㄹ 수 있다 / 없다 Explained
Learn how to say "can" and "can't" in Korean with -(으)ㄹ 수 있다 and 없다. Build 갈 수 있어요 and 먹을 수 있어요, compare it with 못, and meet 할 줄 알다.
BeginnerWant, can, must7 min readTap any Korean word to see it explained
The short answer
To say “can”, add ㄹ 수 있어요 to a verb stem that ends in a vowel, or 을 수 있어요 after a consonant: 갈 수 있어요 (I can go), 먹을 수 있어요 (I can eat). For “can’t”, change 있어요 to 없어요: 갈 수 없어요.
The word 수 means something like “a way” or “a means”. So 갈 수 있어요 is literally “there is a way to go”, and 갈 수 없어요 is “there is no way to go”. Once you see it like that, the pattern makes a lot of sense. Tap the chips below to see each part.
1. Verb + (으)ㄹ 수 있어요: can
Take the dictionary form and drop 다. Then look at the last sound of the stem:
- Ends in a vowel: add ㄹ under it. 가다 becomes 갈 수 있어요.
- Ends in a consonant: add 을. 먹다 becomes 먹을 수 있어요.
Raise your voice at the end and it becomes a question: 내일 갈 수 있어요? (Can you go tomorrow?)
2. (으)ㄹ 수 없어요: can’t
For “can’t”, keep everything the same and swap 있어요 (there is) for 없어요 (there isn’t). “There is no way to...”
For the past, put the past tense on 있다 or 없다 at the end: 갈 수 있었어요 (I could go), 갈 수 없었어요 (I couldn’t go).
This 잘 is 자다 (to sleep), not the adverb 잘 (well). Context makes it clear.
3. ㄹ-stem verbs: 만들 수 있어요
Some verbs already end in ㄹ, like 만들다 (make), 살다 (live) and 놀다 (play, hang out). The ㄹ is already there, so you add nothing. Just put 수 있어요 after the stem.
| Dictionary form | Can | Can’t |
|---|---|---|
| 가다 (go) | 갈 수 있어요 | 갈 수 없어요 |
| 하다 (do) | 할 수 있어요 | 할 수 없어요 |
| 먹다 (eat) | 먹을 수 있어요 | 먹을 수 없어요 |
| 읽다 (read) | 읽을 수 있어요 | 읽을 수 없어요 |
| 만들다 (make) | 만들 수 있어요 | 만들 수 없어요 |
| 살다 (live) | 살 수 있어요 | 살 수 없어요 |
| 듣다 (listen) | 들을 수 있어요 | 들을 수 없어요 |
| 돕다 (help) | 도울 수 있어요 | 도울 수 없어요 |
The last two are irregular verbs. Their stems change shape before a vowel, just like they do in 들어요 and 도와요. Don’t worry about them too much yet. Tapping a word always shows you its dictionary form.
4. Possibility: “it could happen”
The same pattern also talks about what is possible, not just what someone is able to do. Adding 도 (also, even) to 수 gives 수도 있어요: “it might” or “it could”.
A very common, kind reply when someone explains a mistake or a feeling.
5. 수 없어요 vs 못
You may already know 못, which goes in front of a verb: 못 가요 (I can’t go). It means the same as 갈 수 없어요. In everyday talk, 못 is shorter and more common. 수 없어요 sounds a little firmer and more careful, and you will see it a lot in writing and on signs.
With 하다 verbs, 못 goes between the noun and 해요: 수영 못 해요. The 수 form is 수영할 수 없어요.
For more on 못 and its cousin 안, see 안 vs 못 (don’t vs can’t).
6. Knowing how: 할 줄 알아요
When “can” means a skill you learned, like driving or playing piano, Koreans often use 줄 알다 (know the way) instead. For “don’t know how”, use 모르다: 할 줄 몰라요.
Hear it in songs
Songs say “I can’t live without you” a lot, and in Korean that is 수 없어. Open a song in Hanbok Lyrics and tap a line to see every part explained. Next, learn how to say “have to” with 아/어야 하다, or review wishes with -고 싶다 (want to).
Check yourself
Quick check · 1 of 4먹다 (eat) + "can" = ?
The stem 먹 ends in a consonant.
Questions learners ask
How do you say "can" in Korean?
Add ㄹ 수 있다 to a verb stem ending in a vowel, or 을 수 있다 after a consonant. In polite speech: 갈 수 있어요 (I can go), 먹을 수 있어요 (I can eat).
How do you say "can't" in Korean?
Swap 있다 for 없다: 갈 수 없어요 (I can't go). You can also put 못 in front of the verb: 못 가요. Both mean the same thing. 못 is shorter and very common in speech.
What is the difference between 할 수 있다 and 할 줄 알다?
할 수 있다 means you are able to do something right now or in this situation. 할 줄 알다 means you know how, because you learned the skill: 운전할 줄 알아요 (I know how to drive).
Why is it 만들 수 있어요 and not 만들을 수 있어요?
Verbs whose stem ends in ㄹ, like 만들다, 살다 and 놀다, already have the ㄹ sound. You just add 수 있어요 straight after the stem: 만들 수 있어요, 살 수 있어요.