Verbseoul.
하다 verb (adj)
친절하다chinjeolhadato be kind, to be cordial

To say to be kind, to be cordial politely in the present tense, use 친절해요 (cheen-chuhl-hae-yoh). Below is the full conjugation of 친절하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
친절해
cheen-chuhl-hae
친절해요
cheen-chuhl-hae-yoh
친절합니다
cheen-chuhl-hahm-nee-dah
Past
친절했어
cheen-chuhl-hae-ssuh
친절했어요
cheen-chuhl-hae-ssuh-yoh
친절했습니다
cheen-chuhl-hae-sseum-nee-dah
Future
친절할 거야
cheen-chuhl-hahl- -guh-yah
친절할 거예요
cheen-chuhl-hahl- -guh-yae-yoh
친절할 겁니다
cheen-chuhl-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
친절하세요
cheen-chuhl-hah-sae-yoh
Suggestion / Let's Polite (요)
친절해요
cheen-chuhl-hae-yoh
Question Polite (요)
친절해요?
cheen-chuhl-hae-yoh-?
Connective “and” — (고)
친절하고
cheen-chuhl-hah-goh
Conditional “if” — (면)
친절하면
cheen-chuhl-hah-myuhn
Noun form — (기)
친절함
cheen-chuhl-hahm