Korean Grammar Basic #1 – How to Use “이다 / 아니다” (To Be & Not To Be)
- Lee Serene
- Oct 23, 2025
- 2 min read
Updated: Oct 24, 2025
Learn how to use 이다 / 아니다 (to be / not to be) in Korean the foundation of every sentence!
1️⃣ Introduction
The most basic Korean sentence pattern uses 이다 (i-da) — to be — and 아니다 (a-ni-da) — not to be.You’ll hear these forms in every Korean conversation — so let’s master them from the beginning!
In Korean, 이다 (i-da) means “to be”, and 아니다 (a-ni-da) means “not to be.”They don’t look like English am/is/are, but they work the same way — to connect the subject and the noun.
2️⃣ Grammar Explanation
🔹 이다 (i-da) — to be
Dictionary (infinitive) form: 이다 (i-da)
In real conversation, we don’t say “이다” by itself.Instead, we use 이에요 (i-e-yo) or 예요 (ye-yo) depending on the previous sound.
Ending | Rule | Example | Meaning |
이에요 (i-e-yo) | After a consonant | 책이에요 (chae-gi-e-yo) | It’s a book. |
예요 (ye-yo) | After a vowel | 학교예요 (hak-gyo-ye-yo) | It’s a school. |
Pronunciation Tips:
“이에요” often sounds like [이예요 i-ye-yo] in natural speech (slight glide).
Both are polite endings used in everyday speech.
Example Sentences:
저는 선생님이에요. (jeo-neun seon-saeng-nim-i-e-yo) → I am a teacher.
여기는 카페예요. (yeo-gi-neun ka-pe-ye-yo) → This is a café.
🔹 아니다 (a-ni-da) — not to be
Dictionary (infinitive) form: 아니다 (a-ni-da)
Polite speech form: 아니에요 (a-ni-e-yo)
Form | Example | Meaning |
아니다 (a-ni-da) | 학생이 아니다 (hak-saeng-i a-ni-da) | not a student (plain form) |
아니에요 (a-ni-e-yo) | 학생이 아니에요 (hak-saeng-i a-ni-e-yo) | I’m not a student (polite form) |
Pronunciation Tips:
Always use 이/가 (i/ga) before “아니에요.”
❌ 저는 학생은 아니에요 → ✔ 저는 학생이 아니에요.
“아니에요” is often used in polite denials or soft corrections.
Example Sentences:
저는 일본 사람이 아니에요. (jeo-neun il-bon sa-ra-mi a-ni-e-yo) → I’m not Japanese.
여기는 도서관이 아니에요. (yeo-gi-neun do-seo-gwa-ni a-ni-e-yo) → This isn’t a library.
3️⃣ Difference Between “이에요 / 예요” and “아니에요”
Grammar | Politeness | Used After | Correct Example |
이에요 (i-e-yo) | Polite | Consonant-final noun | 학생이에요 (hak-saeng-i-e-yo), 책이에요 (chae-gi-e-yo) |
예요 (ye-yo) | Polite | Vowel-final noun | 의사예요 (ui-sa-ye-yo), 학교예요 (hak-gyo-ye-yo), 친구예요 (chin-gu-ye-yo) |
아니에요 (a-ni-e-yo) | Polite Negative | (Always with 이/가) | 의사가 아니에요 (ui-sa-ga a-ni-e-yo), 학생이 아니에요 (hak-saeng-i a-ni-e-yo) |
4️⃣ Mini Practice
Fill in the blanks 👇
이것은 책______.
저는 학생______.
이것은 사과______.
아니요, 커피______.
저는 의사______.
Answers: (1) 이에요 (2) 이에요 (3) 예요 (4) 가 아니에요 (5) 예요
Vocabulary Check
Word | Pronunciation | Meaning |
책 | (chaek) | book |
학생 | (hak-saeng) | student |
사과 | (sa-gwa) | apple |
커피 | (keo-pi) | coffee |
의사 | (ui-sa) | doctor |
저 | (jeo) | I |
Summary
이다 (i-da) → to be → polite: 이에요 / 예요
아니다 (a-ni-da) → not to be → polite: 아니에요
Always use 이/가 before 아니에요, not 은/는.
📂 Download Practice File
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📥 Download today’s worksheet and practice “이에요 / 예요 / 아니에요” with real examples!
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