高三英语知识点必修二：since从句的用法.docx

高三英语知识点必修二：since
从句的用法
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 e 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，具有否认意 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，那么表示 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 Republie 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，含有否认的意味。
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*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，均含有否认意味。
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.
我已经很久没有见到你了。
另外，①根据英语惯用法，since从句不可以否认形式出 现。
例如：
It is four years since I have smoked a cigarette. 我已经4年不抽烟了。
不可说：It is four years since I haven, t smoked a cigarette.
但由于下句中的since不作“自从”解，所以从句可以 用否认形式。
例如：
I haven' t been out anywhere since I don' t know how long.
也不知多久了，我哪儿也没去过。
②Since从句通常不与非延续性动词的现在完成时的肯定 式连用。
例如：
Her mother died when she was a child.
她小时候母亲就去世了。
不可说：Her mother has died since she was a child.
③Since前不可加表示时间的词语，但可以与ago连用。
例如：
She has lived with us since her mother died three years ago.
自从她母亲3年前去世，她就一直和我们住在一起。
不可说：She has lived with us three years since her mother died.
④在 It was five years ago since his father died. 一句中的since用错了，因为在含有ago的时间范畴里，已 经有了从过去的一个时间点以来的时间，即已有了 since的 时间范畴，所以再用since是多余的。
改为：
It was five years ago that his father died.
他父亲5年前去世了。
It is five years since his father died.
他父亲去世已经5年了。