Verbseoul.
하다 verb (adj)
이상하다isanghadato be strange, to be unusual

To say to be strange, to be unusual politely in the present tense, use 이상해요 (ee-sahng-hae-yoh). Below is the full conjugation of 이상하다 across the three tenses and three everyday speech levels.

Conjugation table

TenseCasual (반말)Polite (요)Formal (합니다)
Present
이상해
ee-sahng-hae
이상해요
ee-sahng-hae-yoh
이상합니다
ee-sahng-hahm-nee-dah
Past
이상했어
ee-sahng-hae-ssuh
이상했어요
ee-sahng-hae-ssuh-yoh
이상했습니다
ee-sahng-hae-sseum-nee-dah
Future
이상할 거야
ee-sahng-hahl- -guh-yah
이상할 거예요
ee-sahng-hahl- -guh-yae-yoh
이상할 겁니다
ee-sahng-hahl- -guhm-nee-dah

Other useful forms

Command Polite (세요)
이상하세요
ee-sahng-hah-sae-yoh
Suggestion / Let's Polite (요)
이상해요
ee-sahng-hae-yoh
Question Polite (요)
이상해요?
ee-sahng-hae-yoh-?
Connective “and” — (고)
이상하고
ee-sahng-hah-goh
Conditional “if” — (면)
이상하면
ee-sahng-hah-myuhn
Noun form — (기)
이상함
ee-sahng-hahm