To Be

Korean Grammar 1

Course 1 · Chapter 5 · To Be

🟰 To Be — 이다 와 아니다

You have been reading sentences like 저는 학생이에요 since Korean Grammar 1, chapter 1 without being told how they are built. This chapter explains them. Korean has two words for "to be" when you want to say what something is: 이다 ("is") and 아니다 ("is not"). They join a noun to its description: "A is B" and "A is not B".

The rule in one box A is B: A + 은/는 + B + 이에요 (after a consonant) or 예요 (after a vowel).
A is not B: A + 은/는 + B + 이/가 아니에요.
The B word is a noun (a student, a doctor, a book). Describing words such as "big" or "cold" are a different kind of word, taken in Korean Grammar 1, chapter 8.

이다: "A is B"

The dictionary form is 이다, but you never meet it on its own. It is joined directly to the noun (no space), and takes the everyday polite ending -요. The form depends on the last sound of the noun:

Noun ends in	Polite form	Example
a consonant	-이에요 -ieyo	학생이에요. haksaeng-ieyo. (I) am a student.
a vowel	-예요 -yeyo	의사예요. uisa-yeyo. (I) am a doctor.

Noun	Ends in	Sentence
책 book	consonant	책이에요. chaeg-ieyo. [채기에요] It is a book.
선생님 seonsaengnim teacher	consonant	선생님이에요. seonsaengnim-ieyo. (He/she) is a teacher.
친구 friend	vowel	친구예요. chingu-yeyo. (He/she) is a friend.
의사 doctor	vowel	저는 의사예요. jeo-neun uisa-yeyo. I am a doctor.
한국 사람 hanguk saram Korean (person)	consonant (람 ends in ㅁ)	저는 한국 사람이에요. jeo-neun hanguk saram-ieyo. I am Korean.

Watch out: no "he/she/it" and no "I/you" needed 친구예요 alone can mean "(he) is a friend", "(she) is a friend", "(it) is a friend" or "(you) are a friend". Korean Grammar 1, chapter 1 explained why: the subject is dropped when it is clear. Add 저는, 이분은 (this person) or a name only when you need to.

Who, what, where: question words with 이다

Question words are nouns, so they take 이다 in the same way. 뭐, 누구 and 어디 all end in a vowel, so they take 예요.

Question	Meaning
뭐예요? mwo-yeyo?	What is it?
누구예요? nugu-yeyo?	Who is it?
어디예요? eodi-yeyo?	Where is it? (What place is it?)

This, that, and that over there

Word	Meaning	Example
이것 igeot	this (near me)	이것은 책이에요. igeos-eun chaeg-ieyo. This is a book.
그것 geugeot	that (near you)	그것은 뭐예요? geugeos-eun mwo-yeyo? What is that?
저것 jeogeot	that over there (far from both)	저것은 학교예요. jeogeos-eun hakgyo-yeyo. That over there is a school.

Watch out: 저 means two different things 저 by itself is "I" (the polite word from Chapter 3) and the "that over there" in 저것. Position tells you which: 저는 is "I", while 저것은 or 저 책 points at something. In speech, 이것 is often shortened to 이거, and 그것 and 저것 to 그거 and 저거.

아니다: "A is not B"

The negative is a separate word, 아니다, not 이다 with a "not". Its polite form is 아니에요 anieyo. The noun that you deny takes the subject particle 이/가 (Korean Grammar 1, chapter 3), and 아니에요 is written as a separate word after it.

Form	Example	Meaning
consonant + 이	저는 학생이 아니에요. jeo-neun haksaeng-i anieyo.	I am not a student.
vowel + 가	저는 의사가 아니에요. jeo-neun uisa-ga anieyo.	I am not a doctor.
with 도 (not … either)	친구도 학생이 아니에요. chingu-do haksaeng-i anieyo.	My friend is not a student either.

Watch out: 아니에요 is both "is not" and "no" 아니에요 is a full sentence that can mean "No, it isn't". The plain word for "no" is 아니요 aniyo; "yes" is 네 ne. They answer questions of any kind, not just ones with 이다.

Questions and answers

Question	Yes	No
학생이에요? haksaeng-ieyo? Are you a student?	네, 학생이에요. ne, haksaeng-ieyo.	아니요, 학생이 아니에요. aniyo, haksaeng-i anieyo.
의사예요? uisa-yeyo? Are you a doctor?	네, 의사예요. ne, uisa-yeyo.	아니요, 의사가 아니에요. aniyo, uisa-ga anieyo.

Note the answer pattern: a Korean "yes" or "no" agrees with the fact, not with the way the question was put. 학생이 아니에요? ("Aren't you a student?") is answered 네 if you are not a student, because it agrees with the "not" in the question. Be ready for this: it is the opposite of the usual English habit.

The formal form: 입니다 and 아닙니다

The ending -입니다 -imnida (said [임니다]) is the formal form of 이다, and 아닙니다 animnida (said [아님니다]) of 아니다. They do not change with the last sound of the noun. You will hear them in announcements, news, and meeting people formally: 저는 학생입니다. jeo-neun haksaeng-imnida. The levels of politeness are laid out in Korean Grammar 1, chapter 10.

	Everyday polite	Formal
is (after a consonant)	학생이에요	학생입니다 / 의사입니다
is (after a vowel)	의사예요	학생입니다 / 의사입니다
is not	학생이 아니에요	학생이 아닙니다

Watch out: 이다 is not "there is" or "have" Do not use 이다 for existence. "There is a cat" and "(I) have a book" are said with 있다: 고양이가 있어요 (Korean Grammar 1, chapter 3), 책이 있어요 (I have a book). 이다 only joins two nouns.

🗣️ In Use — 실제 예문

Short introductions and questions. Pick out the 예요 and 이에요.

① Meeting

A: 저는 민수예요. 학생이에요? jeo-neun minsu-yeyo. haksaeng-ieyo? I'm Minsu. Are you a student?

B: 네, 저는 지연이에요. 학생이에요. ne, jeo-neun jiyeon-ieyo. haksaeng-ieyo. Yes, I'm Jiyeon. I'm a student.

② What is this?

A: 이것은 뭐예요? igeos-eun mwo-yeyo? What is this?

B: 책이에요. 저것은 학교예요. chaeg-ieyo. jeogeos-eun hakgyo-yeyo. It's a book. That over there is a school.

📋 Quick Reference — 요약표

Meaning	After a consonant	After a vowel
is (polite)	-이에요	-예요
is (formal)	-입니다
is not (polite)	-이 아니에요	-가 아니에요
is not (formal)	-이 아닙니다	-가 아닙니다
this / that / that over there	이것 / 그것 / 저것
what / who / where is it?	뭐예요 / 누구예요 / 어디예요
yes / no	네 / 아니요

✏️ Try It Yourself — 연습

Work out the answer first, then click to check.

1. Choose 이에요 or 예요: 선생님__, 친구__, 의사__, 책__.

Show answer

선생님이에요, 친구예요, 의사예요, 책이에요.

2. Say "I am a teacher."

Show answer

저는 선생님이에요. (jeo-neun seonsaengnim-ieyo.)

3. Make this negative: 저는 의사예요.

Show answer

저는 의사가 아니에요. The noun takes 가 (vowel) and 아니에요 follows as a separate word.

4. Make this negative: 이것은 책이에요.

Show answer

이것은 책이 아니에요. (책 ends in a consonant, so 이.)

5. How do you ask "What is that over there?"

Show answer

저것은 뭐예요? (jeogeos-eun mwo-yeyo?)

6. Someone asks 학생이에요? You are a doctor. Answer politely in full.

Show answer

아니요, 학생이 아니에요. 의사예요.

7. What does 저 mean in 저는 and in 저것?

Show answer

In 저는 it means "I". In 저것 it means "that over there". Same spelling, different words.

8. Give the formal version of 저는 학생이에요, and say how it is pronounced.

Show answer

저는 학생입니다. Said [저는 학쌩임니다]: the ㅂ of 입 becomes ㅁ before the ㄴ of 니 (nasalisation, Korean Grammar 1, chapter 2).

9. Say "My friend is not a doctor either" using 도.

Show answer

친구도 의사가 아니에요.

10. Which verb, not 이다, do you use for "There is a book"?

Show answer

있다: 책이 있어요.

Coming up in Chapter 6: Verbs 1: The Everyday Polite Present. You will learn how any ordinary verb is turned into its polite present form, starting from the dictionary form ending in 다, and how the many verbs ending in 하다 work.