A1
고 싶다 — wanting to
How Korean expresses wanting with 고 싶다, why the object may take 이/가, and the separate form needed for a third person.
Drop 다, add 고 싶다. One form regardless of the vowel.
가고 싶어요.
Gago sipeoyo.
I want to go.
한국에 가고 싶어요.
Hanguge gago sipeoyo.
I want to go to Korea.
The object can take 이/가
Because 싶다 is an adjective describing a state, the object may switch from 을/를 to 이/가. Both are correct and 을/를 is more common in speech.
물이 마시고 싶어요.
Muri masigo sipeoyo.
I want a drink of water.
Only about yourself
Like Japanese たい, this states an internal feeling, and Korean will not let you assert someone else’s. About a third person the form is 고 싶어하다.
친구가 가고 싶어요.
친구가 가고 싶어해요.
You can only report that your friend appears to want it. In a question addressed to the person themselves 고 싶어요 is correct: 가고 싶어요?
Wanting a thing, not an action
For a noun the word is 필요하다 (need) or 갖고 싶다 (want to have). 싶다 always needs a verb in front of it.
새 가방을 갖고 싶어요.
Sae gabang-eul gatgo sipeoyo.
I want a new bag.
물을 싶어요.
물을 마시고 싶어요.
싶다 cannot attach to a noun. Say what you want to do with it.
The past
싶었어요 — I wanted to. The tense goes on 싶다, not on the first verb.
가고 싶었어요.
Gago sipeosseoyo.
I wanted to go.