一个虚拟语气的辨别Were he to come,tell him to ring me up.Were it not

Were he to come=If he were to come=If he came,这是对将来的虚拟假设,对将来的虚拟假设,谓语动词有三种结构：过去式,were to do sth.,should do sth.,可以部分倒装而把if省去掉.
Were it not for your help=If it were not for you help=If you were not to help me(对将来的虚拟假设）