since从句的用法

　　下面是小编整理的一些关于介词since从句的用法的总结， 希望能帮助大家更好地认识since从句，学好英语。

　　1. Since从句为非延续性动词的过去时或现在完成时，时间的起点应该从从句动作完成时刻算起。

　　例如：

　　Things have changed a lot since I wrote to you last time.

　　自我上次给你写信之后，情况已发生了很大的变化。

　　She has lived with us since she has come here.

　　自从她来到这里，就一直和我们住在一起。

　　2. Since从句为延续性动词的一般过去时，表示动作或状态的结束。其含义与动词的词义恰好相反，具有否定意味。

　　例如：

　　All has changed since he was at home.

　　自从他离开家以后，这里的一切都变了。

　　I haven’t written to her since she lived in London.

　　自从离开伦敦以来，我还没有给她写过信。

　　He has never been to see me since I was ill.

　　自从我病愈以来，他一直没有来看我。

　　Two years have passed since I last smoked.

　　我戒烟已经两年了。

　　但如果since从句是延续性动词的现在完成时，则表示动作由开始延续至说话的时候，具有肯定意味。

　　例如：

　　He has never been to see me since I have been ill.

　　自从我生病以来，他一直没有来看我。

　　She has talked little since she has stayed at home.

　　自从她呆在家里以后，就很少讲话。

　　Since we have owned a car， we have gone camping every year.

　　自从我们有了汽车后，年年都去野营。

　　3. 在现代英语中，since从句是延续性动词的一般过去时，有时候也可以表示肯定意味。此时，多半用ever来加强since的语义。

　　例如：

　　She has known me ever since she was a child.

　　她从小就认识我了。

　　I have live here ever since I was born.

　　我生下来就住在这里。