Want To: -고 싶다

To say what you want to do, add -고 싶다 to the verb stem. The stem never changes: 먹다 → 먹고 싶어요 (I want to eat), 가다 → 가고 싶어요, 살다 → 살고 싶어요.

• -고 싶어요: I want to… In a question it means do you want to…?
• -고 싶어 해요: he / she / they want to… Korean uses plain 싶다 only for your own wishes (and to ask you). For someone else, add -어 하다: 동생은 가수가 되고 싶어 해요 (My sibling wants to become a singer). The standard spelling keeps the space, but you will often see 싶어해요 written together.
• -고 싶었어요: I wanted to… (past): 어렸을 때 의사가 되고 싶었어요 (As a child I wanted to be a doctor).

Listen to the question: it tells you who wants something and when.