Verbseoul.
하다 verb (adj)
방대하다bangdaehadato be vast, to be enormous, to be massive

To say to be vast, to be enormous, to be massive politely in the present tense, use 방대해요 (bahng-dae-hae-yoh). Below is the full conjugation of 방대하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
방대해
bahng-dae-hae
방대해요
bahng-dae-hae-yoh
방대합니다
bahng-dae-hahm-nee-dah
Past
방대했어
bahng-dae-hae-ssuh
방대했어요
bahng-dae-hae-ssuh-yoh
방대했습니다
bahng-dae-hae-sseum-nee-dah
Future
방대할 거야
bahng-dae-hahl- -guh-yah
방대할 거예요
bahng-dae-hahl- -guh-yae-yoh
방대할 겁니다
bahng-dae-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
방대하세요
bahng-dae-hah-sae-yoh
Suggestion / Let's Polite (요)
방대해요
bahng-dae-hae-yoh
Question Polite (요)
방대해요?
bahng-dae-hae-yoh-?
Connective “and” — (고)
방대하고
bahng-dae-hah-goh
Conditional “if” — (면)
방대하면
bahng-dae-hah-myuhn
Noun form — (기)
방대함
bahng-dae-hahm