Verbseoul.
하다 verb
조사하다josahadato investigate, to examine

To say to investigate, to examine politely in the present tense, use 조사해요 (choh-sah-hae-yoh). Below is the full conjugation of 조사하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
조사해
choh-sah-hae
조사해요
choh-sah-hae-yoh
조사합니다
choh-sah-hahm-nee-dah
Past
조사했어
choh-sah-hae-ssuh
조사했어요
choh-sah-hae-ssuh-yoh
조사했습니다
choh-sah-hae-sseum-nee-dah
Future
조사할 거야
choh-sah-hahl- -guh-yah
조사할 거예요
choh-sah-hahl- -guh-yae-yoh
조사할 겁니다
choh-sah-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
조사하세요
choh-sah-hah-sae-yoh
Suggestion / Let's Polite (요)
조사해요
choh-sah-hae-yoh
Question Polite (요)
조사해요?
choh-sah-hae-yoh-?
Connective “and” — (고)
조사하고
choh-sah-hah-goh
Conditional “if” — (면)
조사하면
choh-sah-hah-myuhn
Noun form — (기)
조사함
choh-sah-hahm