I also drop this language once a while.
and yea mommy. it's a little bit confusing. I'm not good at explaining.. but will try
They don't have like ownership... but as far as my understanding, if no reference for the sentence, it will stand for the person itself. if it's refering to a third person, the sentence will have 그 (geu, which means he)
and the sentence structure is not like English... confusing! Haha but fun, I must say.
Specific sentence for the above would be
저는 뭔가 먹고 싶어요.
jeoneun meonga meokgo sipeoyo
If I want to say, He wants to eat something, the sentence would be
그는 뭔가 먹고 싶어요.
geuneun meonga meokgo sipeoyo
Note; I'm not sure with the grammar. 는 (neun) is only particle.
Let me give another example,
그는 초콜릿 캔디를 좋아해요
geuneun chokolit gaendireur johahaeyo
-he-chocolate-candy-like
Means
He likes chocolate candy.