"괴물이 사람을 먹고 싶어해요."
Translation:The monster wants to eat a person.
I was going to give the link of one of the course creator's explanations, but I can't find it :)
Anywho, 싶다 is actually an adjective, or at least acts as one. When describing something that we, ourselves want, in the 1st person, we attach 고 to the final verb, and add 싶다 at the end of the construction. So we're left with:
저는 한국어 잘 하고 싶어요
I want to speak Korean well. (Or literally "I want to do Korean well")
When we are speaking about someone or something, or we're speaking in the 3rd person, we need to add 하다 to the end of 싶다 to change it into a verb and make the sentence grammatically correct. So:
그 여자는 선생님 되고 싶어해요
That woman wants to become a teacher.
One more note, if you hear someone ask if somebody else wants something or wants to do something, you'll notice they don't use the 싶어하다 version of the word. This is because they're asking about the other person's 1st person desire, if that makes sense. So for instance:
당신 아무 밥도 먹고 싶지 않습니까?
You don't want to eat anything?
as opposed to
그 사람이 아무 밥도 먹고 싶어하지 않습니까?
That person doesn't want to eat anything?
In essence, if you aren't talking about yourself or others in the 1st person, you can feel pretty safe using 싶어하다, and not 싶다.
Here's a link for some extra learning if you're interested