Let's learn about "나다"

나다 = 나야 : It's me

[other expressions]

- 나다. (to younger people or friends)

- 나야. (to younger people or friends)

- 저예요. (honourific by '-요')

- 접니다! (formal; honourific by '-ㅂ')

[explanations]

* 나 : me (non-honourific word)

* 저 : me (honourific word)

* 이다 : be

* if a word ends in a vowel, "이다" contracted into "다"

- 나이다 --> 나다

- 나이야 --> 나야

- 나이에요 --> 나예요

* a noun + -다 / -야 : a non-honourific descriptive form of 이다

* a noun + -예요 / ㅂ니다 : an honourific descriptive form of 이다 suffix by '-요' / '-ㅂ‘