How to Say I Don't Understand in Korean: 15 Natural Phrases

To say I don't understand in Korean, use 이해가 안 돼요 /iɦeɡa an dwe̞jo/. It is polite, natural, and works when someone’s explanation, instructions, or words do not make sense to you. If you simply do not know an answer, say 잘 모르겠어요 /tɕal moɾɯɡe̞s͈ʌjo/ instead.

Korean has more than 80 million first-language speakers worldwide, according to Ethnologue, and it is the official language of both South Korea and North Korea. That means a phrase that sounds appropriately respectful is as valuable as knowing its dictionary meaning. Korean speakers often soften confusion with polite endings, an apology, or a request for clarification.

If you are still building your core conversation skills, start with Korean hello phrases, then learn these responses for the moments when real speech becomes too fast.

The best Korean phrase for I don't understand

이해가 안 돼요 /iɦeɡa an dwe̞jo/ literally means something like “understanding does not happen.” It is the most useful all-purpose option when you understand the words individually but cannot grasp the meaning, logic, explanation, or situation.

The noun 이해 /iɦe̞/ means understanding or comprehension. The phrase uses 안 /an/, a common negative word, with 되다 /twe̞da/, meaning to become or work out.

Use it in situations like these:

• A colleague explains a task too quickly.
• A teacher gives a grammar explanation.
• You do not understand why a rule exists.
• Someone uses unfamiliar vocabulary.
• A friend tells a complicated story.

For a more formal setting, such as a workplace meeting, customer-service interaction, or interview, use 이해가 안 됩니다 /iɦeɡa an toemni̥da/. The meaning is the same, but the -ㅂ니다 /mnida/ style creates more distance and formality.

Choose the phrase that matches what you mean

English uses “I don’t understand” for several different problems. You may not know a fact, may not have heard the speaker, or may understand the sound but not the meaning. Korean distinguishes these situations more clearly.

이해가 안 돼요

이해가 안 돼요 /iɦeɡa an dwe̞jo/ is for a lack of comprehension. Use it when you heard the information but cannot make sense of it.

You can make it gentler by adding 잘 /tɕal/, which means well: 이해가 잘 안 돼요 /iɦeɡa tɕal an dwe̞jo/, “I do not understand very well.” This version is excellent in lessons because it describes the difficulty without sounding like criticism of the speaker.

잘 모르겠어요

잘 모르겠어요 /tɕal moɾɯɡe̞s͈ʌjo/ means “I am not really sure” or “I do not know well.” It is usually the best choice when someone asks you for information you do not have.

For example, if someone asks where the nearest pharmacy is, 잘 모르겠어요 /tɕal moɾɯɡe̞s͈ʌjo/ is more accurate than 이해가 안 돼요 /iɦeɡa an dwe̞jo/. You understood the question, but you lack the information.

잘 못 알아들었어요

잘 못 알아들었어요 /tɕal mot aɾadɯɾʌs͈ʌjo/ means “I did not catch that well.” Use it when the issue is hearing or processing spoken Korean, not understanding an idea.

The verb 알아듣다 /aɾadɯt̚t͈a/ means to hear and understand what someone says. It is especially useful when there is noise, unfamiliar pronunciation, or fast speech.

This phrase is valuable for Korean dramas and films, too. A single line may contain reduced sounds, regional accent features, or vocabulary outside your level. Replaying a short scene with Korean subtitles is usually more productive than replaying an entire episode passively. Our guide to learning Korean through K-dramas offers a practical way to choose manageable material.

다시 말씀해 주세요

다시 말씀해 주세요 /taɕi mal.s͈ɯmɦe̞ tɕuse̞jo/ means “Please say that again.” This is the best follow-up after you say you did not understand.

The word 말씀 /mal.s͈ɯm/ is an honorific version of 말 /mal/, “words” or “speech.” Saying 말씀해 주세요 /mal.s͈ɯmɦe̞ tɕuse̞jo/ recognizes the other person respectfully, which makes it particularly appropriate with teachers, staff, clients, and elders.

To ask for slower speech, add 천천히 /tɕʰʌntɕʰʌnɦi/, “slowly”:

천천히 말씀해 주세요 /tɕʰʌntɕʰʌnɦi mal.s͈ɯmɦe̞ tɕuse̞jo/, “Please speak slowly.”

뭐라고요?

뭐라고요? /mwʌɾaɡojo/ means “What did you say?” It is a quick response when you did not hear someone. In friendly everyday speech, it is extremely common.

Its weakness is tone. A sharply delivered 뭐라고요? /mwʌɾaɡojo/ can communicate disbelief, annoyance, or confrontation, especially if someone has said something offensive. For a stranger or someone older, use 다시 말씀해 주세요 /taɕi mal.s͈ɯmɦe̞ tɕuse̞jo/ instead.

잘 모르겠어

잘 모르겠어 /tɕal moɾɯɡe̞s͈ʌ/ is the casual version of 잘 모르겠어요 /tɕal moɾɯɡe̞s͈ʌjo/. Use it with close friends, people your age who use casual speech with you, or younger people when the relationship permits it.

Korean speech levels are not simply a matter of formal versus informal grammar. They express social distance, age, workplace roles, and the relationship between speakers. Ho-min Sohn’s The Korean Language explains how these endings structure everyday interpersonal communication, not merely sentence style.

A natural three-step response

When you do not understand Korean, avoid freezing after one sentence. A simple sequence gives the other person a clear way to help you.

1. Apologize lightly: 죄송하지만 /tɕoesoŋɦatɕiman/, “I am sorry, but.”
2. Explain the issue: 이해가 잘 안 돼요 /iɦeɡa tɕal an dwe̞jo/.
3. Make a specific request: 천천히 다시 말씀해 주세요 /tɕʰʌntɕʰʌnɦi taɕi mal.s͈ɯmɦe̞ tɕuse̞jo/.

Together, this becomes:

죄송하지만, 이해가 잘 안 돼요. 천천히 다시 말씀해 주세요.
/tɕoesoŋɦatɕiman iɦeɡa tɕal an dwe̞jo tɕʰʌntɕʰʌnɦi taɕi mal.s͈ɯmɦe̞ tɕuse̞jo/

It means: “Sorry, I do not understand very well. Please say it again slowly.”

This kind of indirect, cooperative wording matters. Brown and Levinson’s Politeness: Some Universals in Language Usage identifies the social work of protecting another person’s public self-image during requests and corrections. In Korean, the polite ending and the modest wording 잘 안 돼요 /tɕal an dwe̞jo/ do that work naturally.

Useful variations for class, travel, and work

In a Korean class

Say 이 단어를 잘 모르겠어요 /i tanʌɾɯl tɕal moɾɯɡe̞s͈ʌjo/, “I do not know this word well.”

For grammar, say 문법을 이해 못 했어요 /munpʌbɯl iɦe̞ mot ɦe̞s͈ʌjo/, “I did not understand the grammar.” Notice that this refers to a past explanation, so 못 했어요 /mot ɦe̞s͈ʌjo/ is natural.

In a shop or restaurant

Say 한국어를 잘 못해요 /ɦanɡuɡʌɾɯl tɕal mot ɦe̞jo/, “I am not very good at Korean,” followed by 천천히 말씀해 주세요 /tɕʰʌntɕʰʌnɦi mal.s͈ɯmɦe̞ tɕuse̞jo/.

This is a useful travel phrase, but do not assume English will follow automatically. In many cases, a smile, a short polite request, and a willingness to try Korean will lead to a clearer explanation or gestures. Pair it with the phrases in our Korean restaurant guide.

At work or in a formal setting

Use 이해가 잘 안 됩니다 /iɦeɡa tɕal an toemni̥da/, “I do not understand very well,” or 다시 설명해 주시겠습니까? /taɕi sʌlmjʌŋɦe̞ tɕuɕiɡe̞s͈sɯmnik͈a/, “Could you explain it again?”

The second phrase is formal and suitable for meetings. You do not need to use it during every interaction, but it is useful to recognize in professional dramas, offices, and customer-facing environments.

Common mistakes learners make

Using 몰라요 for every kind of confusion

몰라요 /moɭɭajo/ means “I do not know.” It is not wrong, but it does not mean “I did not understand what you said.” If someone gives directions and you answer 몰라요 /moɭɭajo/, they may think you are refusing to engage or saying you lack knowledge.

Choose 이해가 안 돼요 /iɦeɡa an dwe̞jo/ for meaning and 잘 못 알아들었어요 /tɕal mot aɾadɯɾʌs͈ʌjo/ for sound.

Saying 이해 안 해요

Learners sometimes build a direct negative from English and say 이해 안 해요 /iɦe̞ an ɦe̞jo/. This can mean “I do not understand,” but it may also sound like “I do not choose to understand,” depending on context.

이해가 안 돼요 /iɦeɡa an dwe̞jo/ is the smoother default because it frames understanding as something that is not occurring, rather than an action you are refusing to do.

Confusing 못 and 안

안 /an/ usually marks a general negative, while 못 /mot/ often signals inability. Compare 이해가 안 돼요 /iɦeɡa an dwe̞jo/, “I do not understand,” with 이해 못 해요 /iɦe̞ mot ɦe̞jo/, “I cannot understand.”

Both are used, but the first is more idiomatic as a standalone response. The National Institute of Korean Language dictionary is a reliable reference for checking these forms and their usage.

Build confidence by asking for help

Saying you do not understand is not a failure in Korean conversation. It is a practical social skill. A specific and polite request gives the other person a way to slow down, repeat a word, or explain more simply.

Start with 이해가 안 돼요 /iɦeɡa an dwe̞jo/, then learn the distinction between 잘 모르겠어요 /tɕal moɾɯɡe̞s͈ʌjo/ and 잘 못 알아들었어요 /tɕal mot aɾadɯɾʌs͈ʌjo/. Once these feel automatic, you can handle far more real conversations than vocabulary lists alone allow.

For more polite everyday Korean, review how to say goodbye in Korean and practice phrases in context with real clips on Wordy's Korean learning page.