Verbseoul.
하다 verb (adj)
신중하다sinjunghadacareful, prudent, cautious

To say careful, prudent, cautious politely in the present tense, use 신중해요 (sheen-choong-hae-yoh). Below is the full conjugation of 신중하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
신중해
sheen-choong-hae
신중해요
sheen-choong-hae-yoh
신중합니다
sheen-choong-hahm-nee-dah
Past
신중했어
sheen-choong-hae-ssuh
신중했어요
sheen-choong-hae-ssuh-yoh
신중했습니다
sheen-choong-hae-sseum-nee-dah
Future
신중할 거야
sheen-choong-hahl- -guh-yah
신중할 거예요
sheen-choong-hahl- -guh-yae-yoh
신중할 겁니다
sheen-choong-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
신중하세요
sheen-choong-hah-sae-yoh
Suggestion / Let's Polite (요)
신중해요
sheen-choong-hae-yoh
Question Polite (요)
신중해요?
sheen-choong-hae-yoh-?
Connective “and” — (고)
신중하고
sheen-choong-hah-goh
Conditional “if” — (면)
신중하면
sheen-choong-hah-myuhn
Noun form — (기)
신중함
sheen-choong-hahm