Verbseoul.
ㄹ stem (adj)
힘들다himdeuldadifficult

To say difficult politely in the present tense, use 힘들어요 (heem-deu-ruh-yoh). Below is the full conjugation of 힘들다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
힘들어
heem-deu-ruh
힘들어요
heem-deu-ruh-yoh
힘듭니다
heem-deum-nee-dah
Past
힘들었어
heem-deu-ruh-ssuh
힘들었어요
heem-deu-ruh-ssuh-yoh
힘들었습니다
heem-deu-ruh-sseum-nee-dah
Future
힘들 거야
heem-deul- -guh-yah
힘들 거예요
heem-deul- -guh-yae-yoh
힘들 겁니다
heem-deul- -guhm-nee-dah

Other useful forms

Command Polite (세요)
힘드세요
heem-deu-sae-yoh
Suggestion / Let's Polite (요)
힘들어요
heem-deu-ruh-yoh
Question Polite (요)
힘들어요?
heem-deu-ruh-yoh-?
Connective “and” — (고)
힘들고
heem-deul-goh
Conditional “if” — (면)
힘들면
heem-deul-myuhn
Noun form — (기)
힘듦
heem-deum