【摘要】高一高二的同学忙着准备期中考试的时候，高三的同学们正在进行紧张的高考前地理论复习，下面是准备的“高考英语知识点首轮复习：Since从句的用法”欢迎大家点击参考!
1.高中英语知识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。
4. 在it is+时间+since从句结构中，since从句是非延续性动词的一般过去时，含有肯定意味。
例如：
It is three years since her husband left her.
她丈夫离开她已经3年了。
It is over sixty years since the People’s Republic of China was established.
中华人民共和国已经成立60多年了。
5. 在it is+时间+since从句结构中，since从句是延续性动词的一般过去时，含有否定的意味。
例如：
It is three years since she stayed here.
她离开这里已经3年了。
How long is it since you were a league member?
你退团有多久了?
6. 在it is+时间+since从句结构中，since从句是现在完成时或过去完成时，均含有否定意味。
例如：
It is five years since we have seen her.
我们已经5年没有见她了。
It was years since I had seen her.
在那之前，我已经有好久没有见到她了。
It’s been a long time since I’ve seen you.
总结：以上就是“高考英语知识点首轮复习：Since从句的用法”的全部内容，请大家认真阅读，巩固学过的知识，小编祝愿同学们在努力的复习后取得优秀的成绩!
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