since引導時間狀語從句,此用法較複雜。

(1) 若since引導的狀語從句的謂語動詞是終止性動詞(如go,come,leave,start,begin等)的過去時,則從句表示的時間是“從該動作開始的那一時刻起”.這是最常見的一種用法.如：

He has studied very hard since he came to our school.

自從來到我們學校,他學習就非常努力.

Great changes have taken place in our school since you left.

自從你離開這裡,我們學校發生了很大的變化.

(2) 若since引導的狀語從句的謂語動詞是持續性動詞或表示狀態的靜態動詞(如live,stay,study,learn,smoke,be等)的過去時,則從句表示的時間是“從該動作或狀態的完成或結束時算起”.如：

I haven’t heard from him since he lived here.

這句話應譯為：從他不住這兒起,我一直沒有收到他的信.

I haven’t eaten snakes since I was a student at school.

was表示狀態,因此該句可理解為：I haven’t eaten snakes since I left school.

自從我畢業後就一直沒吃過蛇.

試比較：

He has written to me frequently since I was ill.

自從我病癒以來,他經常給我寫信.(從句謂語為狀態動詞)

He has written to me frequently since I fell ill.

自從我生病以來,他經常給我寫信.(從句謂語為終止性動詞)

(3) 若since引導的狀語從句的謂語為持續性動詞或靜態動詞的現在完成時,則表示動作和狀態延續到現在(說話時刻),其表示的時間的起點應從動作發生之時算起.如：

He has written to me frequently since I have been ill.

這裡have been ill表示狀態的持續性,時間的起點應從：“開始生病”時算起.因此此句可理解為：“自從我生病以來,他經常給我寫信.”

試比較：

I’ve written her 20 letters since I have been here.

自從我來到這,我已經給她寫了20封信.(從開始算起)

I’ve written her 20 letters since I was here.

自從我離開這兒,我已經給她寫了20封信.(從結束算起)

(4) It is + 段時間 + since.../ It has been + 段時間 + since...表示“從……起已有多長時間了”.兩句型意思相同,前者是規範說法,後者是口語說法.

用法：since從句中常用一般過去時,若從句中是持續性動詞的一般過去時,則表示該動作結束有多長時間了.如：

It is three years since he smoked.

他不吸菸已有3年了.

試比較：

It is three years since he began to smoke.

It is three years since he has smoked.兩句均意為：他吸菸已有3年了.

注意：在這種結構中,since引導的從句絕對不能用否定式的謂語動詞來表示否定意義,試比較：

他好久沒學漢語了.

誤：It is a long time since be didn’t study Chinese.

正：It’s a long time since he studied Chinese.

(studied為持續性動詞,應從其動作結束時算起)

since引導時間狀語從句,此用法較複雜。

(1) 若since引導的狀語從句的謂語動詞是終止性動詞(如go,come,leave,start,begin等)的過去時,則從句表示的時間是“從該動作開始的那一時刻起”.這是最常見的一種用法.如：

He has studied very hard since he came to our school.

自從來到我們學校,他學習就非常努力.

Great changes have taken place in our school since you left.

自從你離開這裡,我們學校發生了很大的變化.

(2) 若since引導的狀語從句的謂語動詞是持續性動詞或表示狀態的靜態動詞(如live,stay,study,learn,smoke,be等)的過去時,則從句表示的時間是“從該動作或狀態的完成或結束時算起”.如：

I haven’t heard from him since he lived here.

這句話應譯為：從他不住這兒起,我一直沒有收到他的信.

I haven’t eaten snakes since I was a student at school.

was表示狀態,因此該句可理解為：I haven’t eaten snakes since I left school.

自從我畢業後就一直沒吃過蛇.

試比較：

He has written to me frequently since I was ill.

自從我病癒以來,他經常給我寫信.(從句謂語為狀態動詞)

He has written to me frequently since I fell ill.

自從我生病以來,他經常給我寫信.(從句謂語為終止性動詞)

(3) 若since引導的狀語從句的謂語為持續性動詞或靜態動詞的現在完成時,則表示動作和狀態延續到現在(說話時刻),其表示的時間的起點應從動作發生之時算起.如：

He has written to me frequently since I have been ill.

這裡have been ill表示狀態的持續性,時間的起點應從：“開始生病”時算起.因此此句可理解為：“自從我生病以來,他經常給我寫信.”

試比較：

I’ve written her 20 letters since I have been here.

自從我來到這,我已經給她寫了20封信.(從開始算起)

I’ve written her 20 letters since I was here.

自從我離開這兒,我已經給她寫了20封信.(從結束算起)

(4) It is + 段時間 + since.../ It has been + 段時間 + since...表示“從……起已有多長時間了”.兩句型意思相同,前者是規範說法,後者是口語說法.

用法：since從句中常用一般過去時,若從句中是持續性動詞的一般過去時,則表示該動作結束有多長時間了.如：

It is three years since he smoked.

他不吸菸已有3年了.

試比較：

It is three years since he began to smoke.

It is three years since he has smoked.兩句均意為：他吸菸已有3年了.

注意：在這種結構中,since引導的從句絕對不能用否定式的謂語動詞來表示否定意義,試比較：

他好久沒學漢語了.

誤：It is a long time since be didn’t study Chinese.

正：It’s a long time since he studied Chinese.

(studied為持續性動詞,應從其動作結束時算起)