高三的日子是苦的，有剛?cè)敫呷龝r(shí)的迷茫和壓抑，有成績(jī)失意時(shí)的沉默不語，有晚上奮戰(zhàn)到一兩點(diǎn)的精神肉體雙重壓力，也有在清晨凜冽的寒風(fēng)中上學(xué)的艱苦經(jīng)歷。在奮筆疾書中得到知識(shí)的快樂，也是一種在巨大壓力下顯得茫然無助的痛苦。

　　1. Since從句為非延續(xù)性動(dòng)詞的過去時(shí)或現(xiàn)在完成時(shí)，時(shí)間的起點(diǎn)應(yīng)該從從句動(dòng)作完成時(shí)刻算起。

　　例如：

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

　　自我上次給你寫信之后，情況已發(fā)生了很大的變化。

　　She has lived with us since she has come here.

　　自從她來到這里，就一直和我們住在一起。

　　2. Since從句為延續(xù)性動(dòng)詞的一般過去時(shí)，表示動(dòng)作或狀態(tài)的結(jié)束。其含義與動(dòng)詞的詞義恰好相反，具有否定意味。

　　例如：

　　All has changed since he was at home.

　　自從他離開家以后，這里的一切都變了。

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

　　自從離開倫敦以來，我還沒有給她寫過信。

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

　　自從我病愈以來，他一直沒有來看我。

　　Two years have passed since I last smoked.

　　我戒煙已經(jīng)兩年了。

　　但如果since從句是延續(xù)性動(dòng)詞的現(xiàn)在完成時(shí)，則表示動(dòng)作由開始延續(xù)至說話的時(shí)候，具有肯定意味。

　　例如：

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

　　自從我生病以來，他一直沒有來看我。

　　She has talked little since she has stayed at home.

　　自從她呆在家里以后，就很少講話。

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

　　自從我們有了汽車后，年年都去野營(yíng)。

　　3. 在現(xiàn)代英語中，since從句是延續(xù)性動(dòng)詞的一般過去時(shí)，有時(shí)候也可以表示肯定意味。此時(shí)，多半用ever來加強(qiáng)since的語義。

　　例如：

　　She has known me ever since she was a child.

　　她從小就認(rèn)識(shí)我了。

　　I have live here ever since I was born.

　　我生下來就住在這里。

　　4. 在it is+時(shí)間+since從句結(jié)構(gòu)中，since從句是非延續(xù)性動(dòng)詞的一般過去時(shí)，含有肯定意味。

　　例如：

　　It is three years since her husband left her.

　　她丈夫離開她已經(jīng)3年了。

　　It is over sixty years since the People’s Republic of China was established.

　　中華人民共和國已經(jīng)成立60多年了。

　　5. 在it is+時(shí)間+since從句結(jié)構(gòu)中，since從句是延續(xù)性動(dòng)詞的一般過去時(shí)，含有否定的意味。

　　例如：

　　It is three years since she stayed here.

　　她離開這里已經(jīng)3年了。

　　How long is it since you were a league member?

　　你*有多久了?

　　6. 在it is+時(shí)間+since從句結(jié)構(gòu)中，since從句是現(xiàn)在完成時(shí)或過去完成時(shí)，均含有否定意味。

　　例如：

　　It is five years since we have seen her.

　　我們已經(jīng)5年沒有見她了。

　　It was years since I had seen her.

　　在那之前，我已經(jīng)有好久沒有見到她了。

　　It’s been a long time since I’ve seen you.

　　我已經(jīng)很久沒有見到你了。

　　另

　　①根據(jù)英語慣用法，since從句不可以否定形式出現(xiàn)。

　　例如：

　　It is four years since I have smoked a cigarette. 我已經(jīng)4年不抽煙了。

　　不可說：It is four years since I haven’t smoked a cigarette.

　　但由于下句中的since不作“自從”解，所以從句可以用否定形式。

　　例如：

　　I haven’t been out anywhere since I don’t know how long.

　　也不知多久了，我哪兒也沒去過。

　?、赟ince從句通常不與非延續(xù)性動(dòng)詞的現(xiàn)在完成時(shí)的肯定式連用。

　　例如：

　　Her mother died when she was a child.

　　她小時(shí)候母親就去世了。

　　不可說：Her mother has died since she was a child.

　　③Since前不可加表示時(shí)間的詞語，但可以與ago連用。

　　例如：

　　She has lived with us since her mother died three years ago.

　　自從她母親3年前去世，她就一直和我們住在一起。

　　不可說：She has lived with us three years since her mother died.

　?、茉贗t was five years ago since his father died. 一句中的since用錯(cuò)了，因?yàn)樵诤衋go的時(shí)間范疇里，已經(jīng)有了從過去的一個(gè)時(shí)間點(diǎn)以來的時(shí)間，即已有了since的時(shí)間范疇，所以再用since是多余的。

　　改為：

　　It was five years ago that his father died.

　　他父親5年前去世了。

　　It is five years since his father died.

　　他父親去世已經(jīng)5年了。