Verbseoul.
하다 verb
전화하다jeonhwahadato call by telephone

To say to call by telephone politely in the present tense, use 전화해요 (chuhn-hwah-hae-yoh). Below is the full conjugation of 전화하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
전화해
chuhn-hwah-hae
전화해요
chuhn-hwah-hae-yoh
전화합니다
chuhn-hwah-hahm-nee-dah
Past
전화했어
chuhn-hwah-hae-ssuh
전화했어요
chuhn-hwah-hae-ssuh-yoh
전화했습니다
chuhn-hwah-hae-sseum-nee-dah
Future
전화할 거야
chuhn-hwah-hahl- -guh-yah
전화할 거예요
chuhn-hwah-hahl- -guh-yae-yoh
전화할 겁니다
chuhn-hwah-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
전화하세요
chuhn-hwah-hah-sae-yoh
Suggestion / Let's Polite (요)
전화해요
chuhn-hwah-hae-yoh
Question Polite (요)
전화해요?
chuhn-hwah-hae-yoh-?
Connective “and” — (고)
전화하고
chuhn-hwah-hah-goh
Conditional “if” — (면)
전화하면
chuhn-hwah-hah-myuhn
Noun form — (기)
전화함
chuhn-hwah-hahm