Mixing -요 and -ㅂ니다 in Korean: Meaning, Rules and Examples

What you'll learn

• Explain why switching between -ㅂ니다 and -요 is normal and respectful.
• Assign each ending to a job: acknowledgement, thanks, explanation and question.
• Recognise the fixed expressions that stay formal inside polite talk.
• Avoid the real problem: mixing a respectful ending with a casual one.

Before you start: you should know both endings. The polite -아요/어요 is taught in 해요체 polite speech -아요/어요, and the formal ending is taught in formal speech -ㅂ니다/습니다. Audio plays only when you press a button.

What Does Mixing -요 and -ㅂ니다 in Korean Mean?

Mixing -요 and -ㅂ니다 in Korean means using the formal ending for some sentences and the polite ending for others while talking to the same person. A speech level is a family of sentence endings that shows the relationship between speaker and listener. Both 하십시오체 and 해요체 show respect, so the speaker is still respectful after switching.

Why do speakers mix? The two levels have different feelings. -ㅂ니다 sounds official, careful and distant. -아요/어요 sounds warm, natural and spoken. A person answering a manager usually wants both feelings: careful for the promise, warm for the explanation. Grammar books list the levels as separate columns, but real speakers move between them within a minute.

Two short answers show the habit:

• 네, 알겠습니다. 그런데 저는 내일 못 가요. (ne, algetseumnida. geureonde jeoneun naeil mot gayo.) [네 알겓씀니다 그런데 저는 내일 몯 까요] = "Yes, understood. But I cannot go tomorrow."
• 감사합니다. 정말 맛있어요. (gamsahamnida. jeongmal masisseoyo.) [감사함니다 정말 마시써요] = "Thank you. It is really delicious."

A First Example, Labelled

In the first answer, 알겠습니다 is the formal acknowledgement, "I understand". 그런데 means "but" and starts the explanation. 못 가요 is the polite ending of 가다 with 못, "cannot go". In the second answer, 감사합니다 is a fixed formal thanks, and 맛있어요 is a polite comment. No sentence mixes in a casual ending, and both speakers stay respectful throughout. The next section explains which ending does which job.

How Does Mixing -요 and -ㅂ니다 in Korean Work?

Mixing -요 and -ㅂ니다 in Korean works by giving each ending a job. Use -ㅂ니다 for the moments that need weight: first-meeting greetings, thanks, apologies, promises and announcements. Use -아요/어요 for the moments that need warmth: explanations, questions, opinions and small talk. The switch happens between sentences, not inside one.

Pattern Table

The table lists common jobs with the usual ending and one example.

Three details in the table deserve attention.

First, the formal question ending -ㅂ니까 (갑니까?) is stiff in conversation. News readers, interviewers and customer-service scripts use it. Ordinary speakers ask the same question with -요: 가요?

Second, 하겠습니다 and 알겠습니다 use -겠-, which marks a promise or a decision. The formal level is the natural home for these, because a promise is a serious act.

Third, the honorific marker stays in both levels. 가십니다 (formal) and 가세요 (polite) both respect the person who goes. The lesson on honorific -(으)시- explains the marker.

The table lists the jobs. The worked example shows how a speaker builds a mixed answer.

Worked Example: Building One Mixed Answer

Building a mixed answer takes five steps. The situation: your manager asks you to attend a meeting tomorrow, and you cannot go.

1. Name the listener. The listener is a manager, so every sentence must stay respectful. Casual endings are not available.
2. Acknowledge in the formal level. 네, 알겠습니다. shows that you heard the request. Fixed formal expressions such as 알겠습니다 work in nearly every workplace.
3. Switch to the polite level for the explanation. 그런데 저는 내일 못 가요. is warmer than 그런데 저는 내일 가지 못합니다, and still respectful.
4. Add an honorific or a softener where needed. 죄송하지만 (I am sorry, but) at the start makes the refusal gentler: 죄송하지만 내일은 못 가요.
5. Read the result. 네, 알겠습니다. 그런데 저는 내일 못 가요. (ne, algetseumnida. geureonde jeoneun naeil mot gayo.) = "Yes, understood. But I cannot go tomorrow."

You will know it worked when no sentence in the answer ends in a casual ending such as -아/어 and each ending suits its job. The most common slip is choosing a casual ending in the second sentence because the first sentence felt stiff: 그런데 나 내일 못 가. That version drops the respect the first sentence promised. The next section compares mixing with its risky cousin.

Why Is Polite Plus Formal Fine but Polite Plus Casual Not?

Mixing polite and formal is natural, while mixing polite or formal with casual speech inside one turn is a problem. The reason is respect. Formal and polite both raise the listener, so switching between them keeps the respect. Casual speech (해체, also called 반말) lowers the listener, so a switch to it takes the respect away.

Verdict: mix polite and formal as often as the situation needs, and never drop to casual endings with an elder, a boss or a stranger. If you want to become more casual with a friend, wait until the friend suggests it, as the lesson on when to use polite speech in Korean explains.

An example shows the risk. A new employee says 네, 알겠습니다. 근데 나 내일 못 가. The first sentence is respectful and the second is casual. The manager hears a sudden jump from a subordinate to an equal, and may feel disrespected. The repair is a single change to 근데 저는 내일 못 가요.

The comparison shows the safe side of mixing. The next section covers cases where the rule bends.

When Do You Mix the Levels, and When Not?

Mix the levels according to the setting, and keep four exceptions in mind. Each case gives the rule and an example.

• Fixed expressions stay formal. 감사합니다, 죄송합니다, 알겠습니다, 잘 먹겠습니다 and 잘 먹었습니다 are used even when the rest of the talk is polite. Polite variants exist, such as 죄송해요, but the formal forms are the default.
• One final ending per sentence. A sentence ends only once, so mixing happens between sentences. A connective fragment can take 요, as in 그런데요, 저는 못 가요. Do not stack endings: 갑니다요 and 가요습니다 are not standard.
• Questions favour -요. Between ordinary speakers, 어디 가요? is natural and 어디 갑니까? is stiff. Use -ㅂ니까 in announcements, interviews and formal service scripts.
• 반존대. Half-polite speech mixes -요 and casual endings on purpose, as when an older friend speaks to a younger one. Learners should avoid it with anyone they do not know very well.

An honest limit: how much -ㅂ니다 a workplace expects varies. Military and some company meetings use almost only formal endings, while startups and universities use mostly -요. This lesson gives the safe pattern for a learner. It does not teach the plain style 해라체 or the older levels, which are in the lesson on which Korean speech level to use. The exceptions show that settings decide the mix. The next section lists the mistakes that result.

What Mistakes Do Learners Make When Mixing -요 and -ㅂ니다?

Learners usually make five mistakes, and each has a quick repair.

1. Mixing polite and casual in one turn to an elder. Learners often assume that because mixing -요 and -ㅂ니다 is fine, any mix is fine. Actually, casual -아/어 removes the respect: 네, 알겠어요. 근데 나 못 가. sounds careless. Fix: keep every ending respectful.
2. Believing that you must stay formal all the time. Using only -ㅂ니다 in a café chat makes a speaker sound like a newsreader. Fix: use -요 for chat and keep -ㅂ니다 for the fixed expressions and promises.
3. Using -ㅂ니까 for every question. 뭐 먹습니까? is correct, but stiff between friends or coworkers at lunch. Fix: 뭐 먹어요?
4. Stacking endings. 알겠습니다요 and 가요습니다 are not standard. Fix: finish each sentence with one ending.
5. Treating the switch as inconsistency. Learners sometimes avoid mixing because their textbook says to stay in one level. Fix: remember that a level is a feeling, and a conversation has several feelings.

Use this checklist when a sentence sounds off: Is the ending respectful? Does it match the job of the sentence? Is there only one ending? Practice puts the checklist to work.

Practice and Answers

Try the four items before you read the answer key. Cover the answers with your hand.

1. Choose the form. You thank your teacher. Complete: ___. (감사합니다 / 고마워)
2. Fix the error. A learner says 네, 알겠습니다. 근데 나 못 가. to a manager. Rewrite the second sentence.
3. Translate. "Yes, understood. I am busy today." Use one formal ending and one polite ending.
4. Write your own. Write two sentences to a senior: one that makes a promise and one that explains a problem.

Answer key

1. 감사합니다. It is the fixed formal thanks, and 고마워 is casual.
2. 근데 저는 내일 못 가요. The casual 나 and 가 become 저는 and 가요.
3. 네, 알겠습니다. 오늘은 바빠요. (ne, algetseumnida. oneureun bappayo.) The first sentence is formal and the second is polite.
4. Answers vary. A model pair: 내일까지 하겠습니다. (I will do it by tomorrow.) and 지금은 자료가 없어요. (I do not have the material now.) Check that both endings are respectful and that each suits its job.

A rule of thumb for checking your own work: use -ㅂ니다 when the sentence is a promise, thanks, apology or acknowledgement, and use -요 when the sentence is a question or an explanation.

Next Lessons after Mixing -요 and -ㅂ니다 in Korean

After mixing -요 and -ㅂ니다 in Korean, study the two levels on their own and the decision guide for all levels. This lesson explains how to move between two levels but does not teach every ending in either one.

1. Compare the endings directly in -ㅂ니다 vs -아요/어요.
2. Review the polite level in 해요체 polite speech -아요/어요.
3. Review the formal level in formal speech -ㅂ니다/습니다.
4. Pick a level for any person with which Korean speech level to use.
5. Return to Korean polite speech to see every lesson in the set.

With these steps, mixing -요 and -ㅂ니다 in Korean becomes a habit: formal for weight, polite for warmth, never casual with a senior.

Frequently Asked Questions

Is it rude to mix -요 and -ㅂ니다?

No. Both endings show respect to the listener, so moving between them is normal. A speaker might say 네, 알겠습니다 and then 그런데 저는 내일 못 가요 in the same answer. What is rude is mixing a polite or formal ending with casual -아/어 when speaking to an elder or a stranger.

Should I use -ㅂ니다 or -요 with my boss?

Use both. Choose -ㅂ니다 for acknowledgements, thanks, reports and promises, and -요 for explanations and questions. Many workplaces expect more -ㅂ니다 in meetings and emails, and more -요 in lunch conversations. If you must pick one all day, -요 with honorifics is the safer, friendlier choice.

Why do people say 감사합니다 instead of 감사해요?

감사합니다 is a fixed formal expression. It is the default way to say thanks to almost anyone, even in an otherwise polite chat. 감사해요 is also polite and correct, but it sounds softer and less standard. Fixed expressions such as 죄송합니다 and 알겠습니다 follow the same habit.

Can I mix two levels inside one sentence?

A sentence has one final ending, so mixing happens between sentences, not inside them. A few connective words can take -요 in the middle, as in 그런데요, 저는 못 가요. Do not stack endings such as 갑니다요 or 가요습니다. Finish each sentence with one ending that fits the listener.

What is 반존대, and should I use it?

반존대 means half-polite speech, a mix of -요 and casual endings. Close people use it on purpose, such as an older friend speaking to a younger one, or a child speaking to a parent. A learner should avoid it, because the same mix to a stranger or an elder sounds careless.