Korean - Copula

The term copula refers to the verb that links the subject of a sentence to a noun or adjective, essentially functioning as the equivalent of the English verb "to be" (is, am, are).

In Korean, the primary copula is 이다 (i-da), and its negative form is the existential verb 아니다 (ani-da).

1. The Affirmative Copula: 이다 (i-da)

The copula 이다 is a verb that means "to be" and is attached directly to the noun it defines. It's unique because it is the only Korean verb that attaches directly to a noun without a space.

A. Conjugation

Like all Korean verbs, the copula must be conjugated based on tense and the desired politeness level (speech style). The most common polite forms are:

Preceding Noun Ends In...	Polite Form (해요 Style)	Formal Form (합니다 Style)
Consonant	이에요 (ieyo)	입니다 (imnida)
Vowel	예요 (yeyo)	입니다 (imnida)

B. Examples of Use

Example 1 (Consonant Ending):
- 학생이에요.
- Haksaeng-ieyo.
- (I) am a student. (학생 means 'student')
Example 2 (Vowel Ending):
- 의사예요.
- Uisa-yeyo.
- (He) is a doctor. (의사 means 'doctor')
Example 3 (Formal):
- 저는 한국 사람입니다.
- Jeo-neun hanguk saram-imnida.
- I am a Korean person.

2. The Negative Copula: 아니다 (ani-da)

The verb 아니다 means "to not be" or "is not." Unlike 이다, 아니다 is not a particle; it is a full verb that stands alone, meaning the noun before it must take the Subject Marker (이/가).

A. Structure

The structure for the negative copula is:

Noun + Subject Marker (이/가) + 아니다 (conjugated)

B. Conjugation

The polite form of 아니다 is 아니에요 (anieyo).

C. Examples of Use

Example 4 (Consonant Ending):
- 저는 학생이 아니에요.
- Jeo-neun haksaeng-i anieyo.
- I am not a student.
Example 5 (Vowel Ending):
- 이것은 사과가 아니에요.
- Igeos-eun sagwa-ga anieyo.
- This is not an apple.

Key Points Summary

Feature	Affirmative Copula (이다)	Negative Copula (아니다)
Meaning	To be (is, am, are)	To not be (is not, am not, are not)
Structure	Noun + 이다 (attached)	Noun + 이/가 (Subject Marker) + 아니다 (spaced)
Polite Form	이에요/예요	아니에요
Example	커피예요. (It is coffee.)	커피가 아니에요. (It is not coffee.)