이다 and 아니다
The copula and attach directly to a noun. 이다 and 아니다 are antonyms. 이다 indicates that the subject of the clause is equivalent to the noun it attaches to. 아니다 indicates that the subject of the clause is not equivalent to the noun it attaches to.
follows a noun which ends in a consonant in the intimate speech level.
.
I will introduce (him). He is my younger brother.야 follows a noun which ends in a vowel in the intimate speech level.
이에요 follows a noun which ends in a consonant in the polite speech level.
예요 follows a noun which ends in a vowel in the polite speech level.
, 예요
Teacher, what's this part blocked by the paper?