Question

토요일이라서 백화점에 사람들이 많아요 -이라- and 아니라- are variant forms of -이- and -아니-, respectively. These forms are used before certain verb endings such as -아/어서 and -아/어도.The -이- copula can never be used without a noun.Unlike 아니-, -이- cannot be written spaced from the preceding noun.Independent 아니에요/아닙니다 can be used to convey the meaning of English 'It's nothing' or 'Not really' as an apology or as a polite rejection to a compliment.

Accepted Answer

Because it is Saturday, there are many people in the department store

Front	토요일이라서 백화점에 사람들이 많아요
Back	Because it is Saturday, there are many people in the department store
Notes	-이라- and 아니라- are variant forms of -이- and -아니-, respectively. These forms are used before certain verb endings such as -아/어서 and -아/어도. The -이- copula can never be used without a noun. Unlike 아니-, -이- cannot be written spaced from the preceding noun. Independent 아니에요/아닙니다 can be used to convey the meaning of English 'It's nothing' or 'Not really' as an apology or as a polite rejection to a compliment.

이 Forms Noun 토요일이라서 백화점에 사람들이 많아요 Saturday