Los amigos son simpáticos.
Los because you can see amigos has an O and not an A ; also simpáticos has an O and not an A which indicates it is masculine and Los is masculine, Las is not
Ayer noche, mi hermano llego tarde a la casa.
They really arent anyone. I beleive they're just people.
12 de marzo [3/12]
Hope I helped in some way;)
