Let's learn about "이상한데..."

이상한데 : It's weird

[other expressions]

- 이상하다. (to younger people or friends)

- 이상하네. (to younger people or friends)

- 이상한데. (to younger people or friends)

- 이상해. (to younger people or friends)

- 이상하군! (to younger people or friends)

- 이상하구나! (to younger people or friends)

- 이상하네요. (honourific by '요')

- 이상한데요. (honourific by '요')

- 이상하군요! (honourific by '요')

- 이상해요. (honourific by '요')

- 이상합니다. (formal; honourific by '-ㅂ')

[explanations]

* 이상 : (1) more than; above (2) ideal (3) weirdness

- 3시간 이상 : three hours or more

- 평균 이상이다 : be above average

- 이상과 같이 : as mentioned[stated] above

- 높은 이상을 품다 : have lofty[high] ideals

* 이상한 : weird

* 이상하다 : be weird

* 이상한데 : 이상하(the stem of 이상하다) + -ㄴ데(a non-honourific verb ending suffix; this indicates a little hesitation because something is different from what he expected)

* 이상해 : 이상하(the stem of 이상하다) + -어(a non-honourific verb ending suffix)

* 이상합니다 : 이상하(the stem of 이상하다) + -ㅂ니다(an honourific verb ending suffix by ‘-ㅂ’)

* a verb + -다 / -네 / -어 / -ㄴ데 : a non-honourific descriptive verb ending suffix

* a verb + -군! / -구나! : a non-honourific exclamatory verb ending suffix

* a verb + -네 / -어 / -ㄴ데 / -군! + -요 : an honourific verb ending suffix

* a verb +  -ㅂ니다 : an honourific descriptive verb ending suffix by '-ㅂ'