Posted: 2010-06-18 / Updated: 2018-02-07

To study this grammar point, please make sure you understand the following:

Unlike English, Korean makes no distinction for the choice of verb to be (am, are, is) between first-person, second-person and third-person subjects. Only a single verb to be 이다 is used.

We only attach 이다 (or its modified forms) to nouns and noun phrases.Similarities and Differences Between Korean Verbs and Adjectivesand do not require 이다 for sentence construction.

Summary for Korean Verb To Be 이다 (Present, Past, Present Negative)

Speech LevelPlain FormFormal PoliteInformal PoliteFormal CasualInformal Casual
is, am, are이다입니다이에요/예요인다이야/야
was, were이었다이었습니다이었어요이었다이었어
is not, am not, are not아니다아닙니다아니에요아닌다아니야

Recall that the subject of a sentence can be omitted (if it is understood by the context), and Word Order of Korean Sentences.

  1. 책입니다.
  2. 책이에요.
  3. 책인다.
  4. 책이야.
It is a book.

The Korean sentences above with different Honorific Speech and Speech Levels in Korean convey the same meanings. Notice that (book) is a noun in the sentences.

The choice of 이에요/예요 and 이야/야 is based on Consonant Vowel Sequences in Spoken Korean.

  • If the noun ends with a vowel, use 예요 or 야.
  • If the noun ends with a consonant, use 이에요 or 이야.
It is a bus.
It is a wallet.

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