From http://www.reddit.com/r/Korean/comments/3c85if/%EC%8B%B6%EC%96%B4%ED%95%98%EB%8B%A4_vs_%EC%8B%B6%EB%8B%A4/ 싶어하다 is for other people's desires, while 싶다 is for your own. 영화 보고 싶어요. I want to watch a movie. 우리 언니가 영화 보고 싶어해요. My sister wants to watch a movie. Just want to mention that when you're directly asking someone what they want, you would, of course, still use 싶다. 뭐 하고 싶어? What do you want to do? 싶어하다 is for 3rd person.