Verbseoul.
하다 verb
가설하다gaseolhadato hypothesise, to make a hypothesis

To say to hypothesise, to make a hypothesis politely in the present tense, use 가설해요 (gah-suhl-hae-yoh). Below is the full conjugation of 가설하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
가설해
gah-suhl-hae
가설해요
gah-suhl-hae-yoh
가설합니다
gah-suhl-hahm-nee-dah
Past
가설했어
gah-suhl-hae-ssuh
가설했어요
gah-suhl-hae-ssuh-yoh
가설했습니다
gah-suhl-hae-sseum-nee-dah
Future
가설할 거야
gah-suhl-hahl- -guh-yah
가설할 거예요
gah-suhl-hahl- -guh-yae-yoh
가설할 겁니다
gah-suhl-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
가설하세요
gah-suhl-hah-sae-yoh
Suggestion / Let's Polite (요)
가설해요
gah-suhl-hae-yoh
Question Polite (요)
가설해요?
gah-suhl-hae-yoh-?
Connective “and” — (고)
가설하고
gah-suhl-hah-goh
Conditional “if” — (면)
가설하면
gah-suhl-hah-myuhn
Noun form — (기)
가설함
gah-suhl-hahm