The Arabic sentence "ذهب أبي إلى المستشفى" is translated word by word:
ذهب (dhahaba) = went
أبي (abi) = my father
إلى (ila) = to
المستشفى (al-mustashfa) = the hospital
The correct translation is therefore "My father went to the hospital."
The word أبي specifically means "my father" - not "my brother" (أخي) and not "my uncle" (عمي). The destination المستشفى means "the hospital," not "the market" (السوق). The verb ذهب means "went," indicating departure, not staying at home (بقي في البيت).