이다: The Copula (To Be)

Level: TOPIK 1. 이다 is the Korean copula — the “is/are” word that attaches directly to a noun. Learn it first, because it lets you introduce yourself and name things: 저는 학생이에요 (Jeoneun haksaeng-ieyo, “I am a student”).

The rule

A copula links a subject to a noun. Unlike English, Korean’s copula is attached to the end of the noun, and its polite ending depends on whether that noun ends in a consonant or a vowel:

• Noun ending in a consonant → 이에요: 학생 → 학생이에요.
• Noun ending in a vowel → 예요: 의사 → 의사예요.

The formal-polite form is 입니다 (pronounced imnida), used in announcements, presentations and polite formal speech.

Forms by register and tense

	Informal polite	Formal
Present (“is”)	이에요 / 예요	입니다
Past (“was”)	이었어요 / 였어요	이었습니다 / 였습니다
Negative (“is not”)	…이/가 아니에요	…이/가 아닙니다

The negative uses a separate word, 아니다, with the subject particle 이/가: 학생이 아니에요 (“is not a student”).

Example sentences

Each sentence was written for this lesson (not copied from a third-party corpus), with romanisation.

1. 저는 학생이에요. — Jeoneun haksaeng-ieyo. — I am a student. (consonant → 이에요)
2. 저는 의사예요. — Jeoneun uisa-yeyo. — I am a doctor. (vowel → 예요)
3. 이것은 책이에요. — Igeoseun chaek-ieyo. — This is a book.
4. 그는 선생님입니다. — Geuneun seonsaengnim-imnida. — He is a teacher. (formal)
5. 저는 한국 사람이에요. — Jeoneun hanguk saram-ieyo. — I am Korean.
6. 이것은 물이에요. — Igeoseun mul-ieyo. — This is water.
7. 그것은 제 가방이에요. — Geugeoseun je gabang-ieyo. — That is my bag.
8. 여기는 학교예요. — Yeogineun hakgyo-yeyo. — This place is a school. (vowel → 예요)
9. 이름이 뭐예요? — Ireum-i mwoyeyo? — What is your name?
10. 저는 학생이 아니에요. — Jeoneun haksaeng-i anieyo. — I am not a student. (negative)
11. 그녀는 의사가 아니에요. — Geunyeoneun uisa-ga anieyo. — She is not a doctor.
12. 저는 학생이었어요. — Jeoneun haksaeng-ieosseoyo. — I was a student. (past)

Common mistakes

• ❌ 학생예요 → ✅ 학생이에요. A consonant-final noun needs 이에요.
• After a vowel, 이에요 normally contracts to 예요: 의사예요. The uncontracted 의사이에요 is also standard, but lessons (and most speakers) use 예요. Also note that without 저는, 학생이에요 can mean “I am / you are / he or she is a student” depending on context.
• ❌ 저는 학생 아니에요 → ✅ 저는 학생이 아니에요. In writing and textbooks, keep the particle 이/가 before 아니에요 (it is often dropped in casual speech).
• ❌ 저는 학생이 있어요 (this means “I have a student”) → ✅ 저는 학생이에요. 있다 means “to exist/have”, not “to be a noun”.

Compared with…

• 있다 / 없다 — existence (“there is / isn’t”), not identity. Easy to confuse with 이다.
• Topic particle 은/는 — attaches to the topic noun phrase (not necessarily right before the copula).

Both are listed in the Korean grammar section.

Quick recap before the quiz.

Mini quiz

1. 저는 학생＿＿＿. (polite — consonant noun)
2. 저는 의사＿＿. (polite — vowel noun)
3. 그는 선생님＿＿＿. (formal)
4. 저는 학생＿ 아니에요. (particle)
5. 이름이 뭐＿＿? (“What is your name?”)

Answers

1. 이에요 — 학생 ends in a consonant.
2. 예요 — 의사 ends in a vowel.
3. 입니다 — formal copula.
4. 이 — subject particle before 아니에요.
5. 예요 — 뭐 ends in a vowel.

Sources & licensing

• Forms cross-checked with Wiktionary (CC BY-SA 4.0).
• This is a beginner-level topic; TOPIK I is the beginner exam band (grades 1–2), used here as a general reference, not a per-topic ruling.
• Example sentences were written for this lesson (no third-party sentences copied), with romanisation.

Next

• Back to the Korean grammar section
• New here? Start with Start Learning Korean Here