From : Nancy4366 ( NOT ME) Nancy 4366 who wrote this answer So Here is the lesson on your question. Maybe it will help you. ~ (ㄴ)은데 ~는데 “But, however, so, and” Definition Introductory & Sentence ending > As an introductory ending means “but," “however,” “so,” “and.” indicating a consequent and relevant statement is next. > As a sentence ending it mean a different idea or another possibility, or it can be a signal for feedback. It must be interpreted from context what the speaker is inferring. > It can link sentences together in order to tell a story. Formation Vs + ㄴ데 to a descriptive verb ending in a vowel (present tense) (and the copola) *활발 하다 to be lively, to be active, to be full of life 화발 한데 He) is full of life… Vs + 은데 to a descriptive verb stem ending in a consonant (present tense). *귀찮다 to be annoying 귀찮은데 It is annoying Vs+ 는데 to a verb stem (action verbs, and forms other than the present tense) 쉬다 to rest 쉬는데 She is resting Sentence Examples 이 방이 더운데 (성풍기를 켜줘.) This room is a little hot… (please turn on the fan.) 이거는 맛있는데… (너무 싱거워.) This is delicious… (but it’s too bland) 이거는 맛있는데… (너는 어떻게 생각 해?) This is delicious… what do you think? 이거 무거운데, 들어줘. This is heavy, so please hold it for me. 저는 한국어를 공부하는데, 너무 재미있어요. I’m studying Korean, and it’s so fun. 나 부탁 하나 있는데 I have a favor… (infering: please listen) Notes  이다 becomes '인데'  Verb inflections are inflected before the addition of -ㄴ/은/는데. (e.g. past tense inflection: 봤는데)  If this structure is used as sentence ending, the politeness marker –요, can be added to the end (-ㄴ/은/는데요).

And this is my answer from what i learned hh here is some example Verbs 나오다 (to come out) → 나오는데 집에서 나오는데 비가 와요. (Background) I come out of the house, but it is raining. 시작하다 (to start) → 시작하는데 영화가 시작하는데 극장에 들어가요. (Justification) Since the movie is starting, let’s go inside the theater Adjectives Adjective Stem (Dictionary form -다) + 은/ㄴ데 작다 (to be small)→ 작은데 옷이 작은데 친구 한테 주세요. (Justification) Since the clothes are small, give them to your friend. 편하다 (to be comfortable/convenient)→ 편한데 지하철은 편한데 오래 걸려요. (Contrast) Subway is convenient, but takes long time.

I believe 싶다 is known as an auxiliary adjective.