Verbseoul.
하다 verb
조심하다josimhadato be careful, beware, watch

To say to be careful, beware, watch politely in the present tense, use 조심해요 (choh-sheem-hae-yoh). Below is the full conjugation of 조심하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
조심해
choh-sheem-hae
조심해요
choh-sheem-hae-yoh
조심합니다
choh-sheem-hahm-nee-dah
Past
조심했어
choh-sheem-hae-ssuh
조심했어요
choh-sheem-hae-ssuh-yoh
조심했습니다
choh-sheem-hae-sseum-nee-dah
Future
조심할 거야
choh-sheem-hahl- -guh-yah
조심할 거예요
choh-sheem-hahl- -guh-yae-yoh
조심할 겁니다
choh-sheem-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
조심하세요
choh-sheem-hah-sae-yoh
Suggestion / Let's Polite (요)
조심해요
choh-sheem-hae-yoh
Question Polite (요)
조심해요?
choh-sheem-hae-yoh-?
Connective “and” — (고)
조심하고
choh-sheem-hah-goh
Conditional “if” — (면)
조심하면
choh-sheem-hah-myuhn
Noun form — (기)
조심함
choh-sheem-hahm