"I want my bread."
Translation:Θέλω το ψωμί μου.
In Greek you cannot use the possessive on its own after the noun, the definite article has to accompany the noun.
My yiayia will ask me sometimes "θέλεις ψωμί;" (you want bread?) I think it's like saying "do you want the bread?" vs. "you want bread?" with the first one being more proper and correct but the second being comfortable and easier, but not necessarily incorrect. If you were to sit a Greek test or something and give the second answer, it would probably be marked wrong. But in a casual social setting it's fine :)
It wouldn't be wrong. This is included in the alternative translations. However, if you don't want to give any emphasis on the person, you can omit the personal pronouns in Greek, since there is a different verb form for each pronoun. ^.^