The verb can slightly change depending on the noun you want.
If it is like, "I want that pen."
You would say: 저 펜이 갖고 싶어(요).
If it is like, "I want freedom."
You would say: 자유를 원해(요)
And if it is like, "I want to go there."
You would say: 거기에 가고 싶어요.