The original question is, 'The other, whose parents lived in Greece, was returning home.' My translation is, 'Alter, cuius parentes habitaverunt Graecum, redibat domum,' and i am not so sure if 'in greece'(it would be best to have it in one word) and 'returning home' would be accusative in this context. Any suggestions on what it should be?
- "Graecum" should be "Graeciam" since you want the Place not the Adjective.
- You also will want to change the word order I think -- the verb usually comes at the end of a clause. "Graeciam habitaverunt"
- "Domum" should be "Domi." A locative makes sense here.
Other than that, I think you did a great job. You used perfect tense for a completed occurrence, you used the inceptive imperfect. Habito easily takes an accusative, so no issue there. Well done!
Side note (and this may just be me) but I have never seen "alter" start off a sentence in isolation like this. I would just drop it and start with cuius. "Cuius parentes Graeciam habitaverunt, ille redibat." That man whose parents lived in Greece began to return.
As Nickimite has pointed out, Greece is Graecia, so the accusative would be Graeciam. But that is not how you say where someone is and remains. How exactly you say that depends on how you describe their dwelling place; however for regions and countries it's simply in + ablative – so that would be in Graecia. For the names of cities and small islands and a few special words, you would use the locative, but Greece is not among those. (You can also use apud or ad + accusative to express vicinity, e.g.: ad litora habito = I live by the seashore.)
For motion towards a place, we would usually use in or ad + accusative, but for cities, small islands and a few special words, you use the simple accusative. Domus happens to be such a special word, so we say: domum redire.
Allen & Greenough wrote it all up, read it here.
Note that having lived somewhere is a continuous state, so it qualifies for the imperfect, while having gone somewhere is a single completed action, so you might want to use the perfect tense. That leaves us with:
Alter, cuius parentes in Graecia habitabant, domum rediit.
If you wanted to say: The other, wo lived at his parents' place, went to Italy, you would say:
Alter, qui apud parentis habitabat, in Italiam se contulit.