What is the difference between a verb and a copula

Question

I have a general grammar question. I often see the term copula as it is like different from what a normal verb is.

According to one of my references Basic Korean: A Grammar and Workbook by Andrew Sangpil Byon:

In English, copulas “am,” “are,” and/or “is” can express at least two things. First, they are used to indicate the equational expression (e.g., something equals something), as in “John is a student” or “Hyundai is an automobile company.” In addition, they indicate that something is located or existing as in “There are Korean people” or “Honolulu is in Hawaii.” In Korean, two different words express these two functions. For the equational expression, Korean has the copula 이다 (or 안이다 for negation). For the verb of existence or location, Korean has the verb 있다 (or 없다 for negation).

Am I right in saying that every copula is a verb but not every verb is a copula then? Is it correct to say that "copulas are verbs expressing equational expressions, location or existance"?

Are there other copulas apart from 이다/안이다 and 있다/없다 that are worth knowing?

Maybe this is a silly question but I just want confirmation as I see this term coming up a lot.

Answer 1

As I understand it, a copula is a verb that links (equates) two things, like "A is B" where both A and B are typically nouns. I believe the paragraph you quoted is not entirely accurate in that it includes "Honolulu is in Hawaii" as an example of copula. This "is" means "to exist" which should not be considered a copula.

"be" is the only word that can function as a copula, although some other words like "to mean" can simulate this meaning, as in "Seeing is believing" which can be expressed as "Seeing means believing".

Here's how English's "be" verb maps to Korean words 이다, 있다, and others.

"be" usage	function	Korean word	examples
A is B	copula	이다 / 아니다	나는 학생이다 (I am a student)
A is (somewhere)	existence	있다 / 없다	연못에 오리가 있다 (There is a duck is in the pond)
A is (adjective)	description	(형용사)	나는 행복하다 (I am happy)

The three functions of English's "be" verb maps to three distinct classes of words in Korean.

The copula function is handled by 이다 and its negative (-이/가) 아니다 (e.g. 나는 학생이 아니다 = I am not a student. Note that 안이다 (X) is a wrong spelling). 이다 is technically a particle (and thus directly attaches to a noun in writing) but semantically it functions like an adjective.

Existence is expressed by 있다 and its negative 없다, but there is also 존재한다. 있다 is a common adjective like English's "is" (and "am" and "are" as well), while 존재하다 is more formal and technical word like "exist" in English.

The "be" verb's descriptive function is handled by individual adjectives which function like verbs in Korean. So "The weather is good" would translate to 날씨가 좋다, where 날씨 is the subject, 가 the subject marker particle, and 좋다 the adjective corresponding to "good". 안 좋다 and 좋지 않다 are the two ways to negate the phrase. Unlike in English, an adjective predicates the subject directly with no extra word (an adjective is also called "descriptive verb" for this reason).