내일 온대

they say someone is coming tomorrow

→ 내일
phrase Uncommon #10,209
they say someone is coming tomorrow 온대 is a conversational contraction of 온다고 해, used to report what someone said or what is expected. The subject is understood from context.
KO: 민수는 내일 온대.
EN: They say Minsu is coming tomorrow.

아미 내일 온대

Ami says she's coming tomorrow.

— 중경삼림 (1994)

전문가가 내일 온대

They say the expert is coming tomorrow.

— 마농의 샘 2부 (1986)