연구해
yuhn-goo-hae
yeonguhae
연구하다
To say to conduct research politely in the present tense, use 연구해요 (yuhn-goo-hae-yoh) · yeonguhaeyo. Below is the full conjugation of 연구하다 across the three tenses and three everyday speech levels.
Grammar note (하다 verb): 하다 verbs are formed with a Sino-Korean noun + 하다 (e.g. 공부하다 = study + do). 하다 conjugates irregularly: the ㅏ in 하 contracts with the -아/-어 suffix to give 해 (not *하어). Present polite: 해요; past polite: 했어요. The formal ending is 합니다 (not *하습니다). Most noun+하다 compounds follow this pattern uniformly. See all 하다 verbs →
Conjugation table
pron. = pronunciation guide · RR = Revised Romanization
Highlighted = where the stem changes
| Tense | Casual (반말) | Polite (요) | Formal (합니다) |
|---|---|---|---|
| Present | 연구해요 yuhn-goo-hae-yoh yeonguhaeyo | 연구합니다 yuhn-goo-hahm-nee-dah yeonguhamnida | |
| Past | 연구했어 yuhn-goo-hae-ssuh yeonguhaesseo | 연구했어요 yuhn-goo-hae-ssuh-yoh yeonguhaesseoyo | 연구했습니다 yuhn-goo-hae-sseum-nee-dah yeonguhaesseumnida |
| Future | 연구할 거야 yuhn-goo-hahl guh-yah yeonguhal geoya | 연구할 거예요 yuhn-goo-hahl guh-yae-yoh yeonguhal geoyeyo | 연구할 겁니다 yuhn-goo-hahl guhm-nee-dah yeonguhal geomnida |
Other useful forms
Honorific / Command Polite (-(으)세요)
연구하세요
yuhn-goo-hah-sae-yoh
yeonguhaseyo
Suggestion / Let's Polite (요)
연구해요
yuhn-goo-hae-yoh
yeonguhaeyo
Question Polite (요)
연구해요?
yuhn-goo-hae-yoh-?
yeonguhaeyo?
Connective "and" — (고)
연구하고
yuhn-goo-hah-goh
yeonguhago
Conditional "if" — (면)
연구하면
yuhn-goo-hah-myuhn
yeonguhamyeon
Progressive (고 있어요)
연구하고 있어요
yuhn-goo-hah-goh ee-ssuh-yoh
yeonguhago isseoyo
Want to (고 싶어요)
연구하고 싶어요
yuhn-goo-hah-goh shee-puh-yoh
yeonguhago sipeoyo
Can / Able to ((으)ㄹ 수 있어요)
연구할 수 있어요
yuhn-goo-hahl soo ee-ssuh-yoh
yeonguhal su isseoyo
Because / So (아/어서)
연구해서
yuhn-goo-hae-suh
yeonguhaeseo
Noun form — (기)
연구하기
yuhn-goo-hah-gee
yeonguhagi
Noun form — (음)
연구함
yuhn-goo-hahm
yeonguham