Separate possibility from learned know-how

English “can” covers several different ideas. You might know how to swim, have time to visit a friend or be allowed to take a photo. Korean often makes those differences clearer, especially when the reason matters to the conversation.

할 수 있어요 says that doing something is possible or within your ability. 할 줄 알아요 focuses on knowing how to do it. For permission, 해도 돼요? asks whether it is all right to do something. These distinctions help you explain why an action is possible, rather than translating “can” the same way every time.

Build both ability forms accurately

Suppose you learned to use a program but do not have a computer with you. 파일을 열 줄 알아요 can still be true: you know how to open the file. 지금은 열 수 없어요 explains that you cannot do it right now. The obstacle is the situation, not your knowledge.

The verb stem determines whether you add -ㄹ or -을: 가다 becomes 갈 수 있어요, while 읽다 becomes 읽을 수 있어요. Use the same shape before 줄: 갈 줄 알아요 and 읽을 줄 알아요. Keep the spaces around 수 and 줄 when writing.

Ask about ability without changing the meaning

한국어를 읽을 수 있어요 describes an ability to read Korean. 한국어를 읽을 줄 알아요 emphasizes knowing how to read it. Both may fit the same person; the difference is what the speaker wants to highlight.

오늘은 갈 수 없어요 is especially useful when explaining availability. It does not necessarily mean you are physically unable to go. Time, another appointment or a transport problem may make it impossible today.

Resolve an ambiguous “can” statement

The second speaker knows how to open the file but does not currently have a computer. 열 줄은 알지만 puts that knowledge first; 지금은 컴퓨터가 없어요 then explains the practical obstacle.

The follow-up asks about tomorrow, when the situation may change. 내일은 가능해요 answers that question without repeating the whole explanation. This is why a yes-or-no question about ability sometimes needs a little context.

Check whether the speaker means conditions or skill

At a museum, 사진을 찍어도 돼요? clearly asks for permission. 사진을 찍을 수 있어요? may also be understood as asking whether photography is allowed in that setting, but it can be a question about practical possibility. The permission form makes your intention more explicit.

When you answer a question about a skill, one useful next sentence is how well you can do it. You might know the basics but need help with a difficult task. The forms in this lesson describe knowledge or possibility; they do not by themselves tell the listener your level.

Correct likely misunderstandings

Avoid treating 할 수 있다 and 할 줄 알다 as opposites. A learned skill often makes an action possible, so their meanings can overlap. The choice depends on whether you are discussing know-how or whether something can happen.

줄 알다 also appears in other structures with meanings such as “thought that.” Here the focus is the learned-skill use after an action verb, as in 수영할 줄 알아요. Reading the verb form and the surrounding sentence helps you recognize which meaning is intended.

Try it in a familiar situation

A small listening check

References and useful next steps

• Korean–English Learners’ Dictionary — Check meanings, usage labels, conjugated examples and human recordings for the lesson vocabulary.

Reviewed September 4, 2026. Found a mistake? Send a correction.