"a neighbor and a neighbor"
Well, the problem seems to be that they want you to write "a male neigbour and a female neighbour": Arabic has different words for male and female neighbours, so there is a difference between the two Arabic sentences. However, English only has one ungendered word for neighbour, so you can't indicate that in an English sentence. This keeps happening.
Also the sentence "A neighbour and a neighbour" is just not good English: one would say "two neighbours" or "a pair of neigbours" or something like that.