Verbseoul.
하다 verb (adj)
교활하다gyohwalhadato be crafty, to be sly

To say to be crafty, to be sly politely in the present tense, use 교활해요 (gyoh-hwahl-hae-yoh). Below is the full conjugation of 교활하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
교활해
gyoh-hwahl-hae
교활해요
gyoh-hwahl-hae-yoh
교활합니다
gyoh-hwahl-hahm-nee-dah
Past
교활했어
gyoh-hwahl-hae-ssuh
교활했어요
gyoh-hwahl-hae-ssuh-yoh
교활했습니다
gyoh-hwahl-hae-sseum-nee-dah
Future
교활할 거야
gyoh-hwahl-hahl- -guh-yah
교활할 거예요
gyoh-hwahl-hahl- -guh-yae-yoh
교활할 겁니다
gyoh-hwahl-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
교활하세요
gyoh-hwahl-hah-sae-yoh
Suggestion / Let's Polite (요)
교활해요
gyoh-hwahl-hae-yoh
Question Polite (요)
교활해요?
gyoh-hwahl-hae-yoh-?
Connective “and” — (고)
교활하고
gyoh-hwahl-hah-goh
Conditional “if” — (면)
교활하면
gyoh-hwahl-hah-myuhn
Noun form — (기)
교활함
gyoh-hwahl-hahm