"Te olette aina ystävä" means "you are always a friend". In this case the "te olette" is a way to formally address someone when normally you would say "sinä olet aina ystävä". If you want to say "you are always friends" ="te olette aina ystäviä". "Te" means both you (plural) and you (formal). The formal you is usually used when talking to older people.