Verbseoul.
regular
실망시키다silmangsikidato disappoint

To say to disappoint politely in the present tense, use 실망시켜요 (sheel-mahng-shee-kyuh-yoh). Below is the full conjugation of 실망시키다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
실망시켜
sheel-mahng-shee-kyuh
실망시켜요
sheel-mahng-shee-kyuh-yoh
실망시킵니다
sheel-mahng-shee-keem-nee-dah
Past
실망시켰어
sheel-mahng-shee-kyuh-ssuh
실망시켰어요
sheel-mahng-shee-kyuh-ssuh-yoh
실망시켰습니다
sheel-mahng-shee-kyuh-sseum-nee-dah
Future
실망시킬 거야
sheel-mahng-shee-keel- -guh-yah
실망시킬 거예요
sheel-mahng-shee-keel- -guh-yae-yoh
실망시킬 겁니다
sheel-mahng-shee-keel- -guhm-nee-dah

Other useful forms

Command Polite (세요)
실망시키세요
sheel-mahng-shee-kee-sae-yoh
Suggestion / Let's Polite (요)
실망시켜요
sheel-mahng-shee-kyuh-yoh
Question Polite (요)
실망시켜요?
sheel-mahng-shee-kyuh-yoh-?
Connective “and” — (고)
실망시키고
sheel-mahng-shee-kee-goh
Conditional “if” — (면)
실망시키면
sheel-mahng-shee-kee-myuhn
Noun form — (기)
실망시킴
sheel-mahng-shee-keem