Verbseoul.
하다 verb
장담하다jangdamhadato guarantee

To say to guarantee politely in the present tense, use 장담해요 (chahng-dahm-hae-yoh). Below is the full conjugation of 장담하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
장담해
chahng-dahm-hae
장담해요
chahng-dahm-hae-yoh
장담합니다
chahng-dahm-hahm-nee-dah
Past
장담했어
chahng-dahm-hae-ssuh
장담했어요
chahng-dahm-hae-ssuh-yoh
장담했습니다
chahng-dahm-hae-sseum-nee-dah
Future
장담할 거야
chahng-dahm-hahl- -guh-yah
장담할 거예요
chahng-dahm-hahl- -guh-yae-yoh
장담할 겁니다
chahng-dahm-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
장담하세요
chahng-dahm-hah-sae-yoh
Suggestion / Let's Polite (요)
장담해요
chahng-dahm-hae-yoh
Question Polite (요)
장담해요?
chahng-dahm-hae-yoh-?
Connective “and” — (고)
장담하고
chahng-dahm-hah-goh
Conditional “if” — (면)
장담하면
chahng-dahm-hah-myuhn
Noun form — (기)
장담함
chahng-dahm-hahm