同學(xué)們我們已經(jīng)學(xué)習(xí)了現(xiàn)在進(jìn)行時(shí)、一般現(xiàn)在時(shí)、一般過(guò)去時(shí)、一般將來(lái)時(shí)這4種時(shí)態(tài)的用法，但這4種時(shí)態(tài)還不能滿足我們表達(dá)的需要。比如：表示“某人過(guò)去曾經(jīng)做過(guò)某事”或者“某人做某事多久”，以上五種時(shí)態(tài)就派不上用場(chǎng)了。這時(shí)，我們可以用一種新的時(shí)態(tài)——現(xiàn)在完成時(shí)表示。

一、現(xiàn)在完成時(shí)的構(gòu)成

(一)肯定式

主語(yǔ)+助動(dòng)詞have /has +過(guò)去分詞+其它

說(shuō)明：這里的have /has是助動(dòng)詞，沒有什么具體意義。當(dāng)主語(yǔ)是第三人稱單數(shù)時(shí)助動(dòng)詞用has，其余人稱一律用have。 has，have的縮略式分別為's或've。規(guī)則動(dòng)詞過(guò)去分詞的構(gòu)成與過(guò)去式的構(gòu)成方式一樣，不規(guī)則動(dòng)詞可參看不規(guī)則動(dòng)詞表。實(shí)例：

1)I've just copied all the new words .我剛抄寫了所有的生詞。 (表示不要再抄了)

2)She has lost her books .她丟失了她的書。 (表示到目前為止還沒有找到)

(如果用過(guò)去時(shí)：She lost her books . 則強(qiáng)調(diào)書是過(guò)去丟的這一動(dòng)作，而不知現(xiàn)在有沒有找到)

3)We've just cleaned the classroom .我們剛好打掃了教室。(表明現(xiàn)在教室是干凈的)

(二)否定式

主語(yǔ)+助動(dòng)詞have /has+not+過(guò)去分詞+其它

說(shuō)明：現(xiàn)在完成時(shí)構(gòu)成否定句時(shí)，只需在助動(dòng)詞have /has后面加not就行。have not，has not的縮略式分別為haven't ，hasn't。另外，肯定句中有some，already時(shí)，改為否定時(shí)要分別改成any，yet。實(shí)例：

1)I haven't finished my homework yet.我還沒有完成我的作業(yè)。

2)She hasn't travelled on a train .她沒有坐火車旅行過(guò)。

3)We have never spoken to a foreigner.我們從來(lái)沒有和外國(guó)人說(shuō)過(guò)話。

注：有時(shí)not可以用never代替，表示“從來(lái)沒有”的意思。又如：

4)I have never seen him before.以前我從來(lái)沒有見過(guò)他。

(三)一般疑問式

助動(dòng)詞Have /Has +主語(yǔ)+過(guò)去分詞+其它 ?

說(shuō)明：把陳述句中的have或has放到句首，句末打問號(hào)，同時(shí)把句中的some ，already改為any ，ye t就構(gòu)成了一般疑問句?？隙ɑ卮鹩?ldquo;Yes ，主語(yǔ)+have/has.否定回答用“No，主語(yǔ)+haven't/hasn't.”有時(shí)也可以用“No，not yet./No ，never./No，not even once.”等。實(shí)例：

1)—Have you ever made dumplings ?你曾經(jīng)做過(guò)餃子嗎?

—Yes ，I have .是的，我做過(guò)。

2)—Has she ever been abroad ?她曾經(jīng)出過(guò)國(guó)嗎?

—No，never.不，從來(lái)沒有。

3)—Have they found the lost books yet ?他們已經(jīng)找到了丟失的書嗎?

—Yes ，they have.是的，他們找到了。

注意：當(dāng)句中有否定詞not ，hardly(幾乎不)，never的時(shí)候，在改為反意疑問句時(shí)，附加部分用肯定形式。例如：You have never come to our school ，have you ?你以前從來(lái)沒有來(lái)過(guò)我們學(xué)校，是嗎?

二、現(xiàn)在完成時(shí)的用法

(一)現(xiàn)在完成時(shí)的用法1：表示過(guò)去發(fā)生或已經(jīng)完成的某一動(dòng)作對(duì)現(xiàn)在造成的影響或結(jié)果。此時(shí)，常與時(shí)間副詞already(已經(jīng)) ，yet(還、已經(jīng)) ，just(剛剛、僅僅) ，ever(曾經(jīng)) ，never(從不) ，before(以前)等連用。這幾個(gè)副詞的用法如下：

1.already意為“已經(jīng)”，通常用于肯定句中，可放在助動(dòng)詞之后，過(guò)去分詞之前，也可以放在句末。實(shí)例：

1)I've already read this book. 我已經(jīng)讀過(guò)這本書了。

(“讀”這一動(dòng)作發(fā)生在過(guò)去，對(duì)現(xiàn)在造成的影響是“知道書中的內(nèi)容”。)

2)I've washed my clothes already.我已經(jīng)洗了衣服。

(洗衣服的動(dòng)作已完成，其結(jié)果是“衣服冼干凈了”。)

注意：在表示吃驚或明知故問等感情色彩時(shí)，already也可用于(口語(yǔ))疑問句中。實(shí)例：

3)Have you met him already ?你(真的)已經(jīng)見過(guò)他了?

2.yet用在疑問句中意為“已經(jīng)”，用在否定句中意為“還”，常放在句末。實(shí)例：

1)—Has he found his watch yet ?他已經(jīng)找到他的手表了嗎?

—No，not yet.不，還沒有。

2)The woman hasn't found her dog yet .

那位婦女還沒有找到她的狗。(沒找到狗，心里著急，這就是對(duì)現(xiàn)在的影響)

3.just意為“剛剛”，表示行為剛剛過(guò)去，常放在助動(dòng)詞與過(guò)去分詞之間。實(shí)例：

He has just come back from school .他剛從學(xué)校回來(lái)。

4.ever意為“曾經(jīng)”，用于疑問句或否定句中，放在助動(dòng)詞與過(guò)去分詞之間。實(shí)例：

1)Have you ever been to Hong Kong ?你曾去過(guò)香港嗎?

2)I haven't ever spoken to her.我未曾和她說(shuō)過(guò)話。

5.never意為“從來(lái)沒有”常與before連用(before要放在句尾，而never多放在助動(dòng)詞與過(guò)去分詞之間。實(shí)例：

I have never travelled by plane before.我以前從來(lái)沒有乘飛機(jī)旅行過(guò)。

6.before意為“以前”，指過(guò)去不確定的某個(gè)時(shí)間，總是放在句末，不受句型的限制。實(shí)例：

1)Have you been to Hainan before ?你以前去過(guò)海南嗎?

2)I haven't eaten Guangdong food before.我以前沒吃過(guò)廣東菜。

(二)現(xiàn)在完成時(shí)用法二2——持續(xù)性用法(肯定句，疑問句中謂語(yǔ)動(dòng)詞必須是延續(xù)性動(dòng)詞)：表示過(guò)去已經(jīng)開始，持續(xù)到現(xiàn)在的動(dòng)作或狀態(tài)。此時(shí)常與“for +一段時(shí)間或“since+過(guò)去的點(diǎn)時(shí)間或從句(從句用一般過(guò)去時(shí))以及so far(到目前為止)等時(shí)間狀語(yǔ)連用。

for + 段時(shí)間

since +點(diǎn)時(shí)間

實(shí)例：

1)I've lived here since 1990.自從1990年以來(lái)我就住在這里。

= I've lived here since 13 years ago.

= I've lived here for 13 years.

= It is 13 years since I began to live here.

2)I haven't seen him for three years .我三年沒有看見他了。

= I haven't seen him since three years ago

= I haven't seen him since 2000.

= It is 3 years since I saw him last time.

3)Mr Wang has worked in the factory since he came to the city .

自從到這個(gè)城市以來(lái)，王先生一直在這家工廠工作。

4)She's been at this school since five years ago.

自從五年前以來(lái)她就在這個(gè)學(xué)校。

注意：①在這類句子的肯定句和疑問句中謂語(yǔ)動(dòng)詞必須用延續(xù)性動(dòng)詞。短暫性動(dòng)詞由于動(dòng)作不能持續(xù)，故不能與for(達(dá)到;累計(jì))或since(自從。。。到現(xiàn)在)引出的時(shí)間狀語(yǔ)連用。

②對(duì)for和since引導(dǎo)的時(shí)間狀語(yǔ)提問要用How long

1) 他入團(tuán)兩年了。

誤：He has joined the League for two years.

正：He has been a League member for two years.

2)我買這輛自行車三年了。

誤：I have bought this bike for three years.

正：I have had this bike for three years.

2) ▲部分短暫性動(dòng)詞與之對(duì)應(yīng)的延續(xù)性動(dòng)詞：

短暫性動(dòng)詞 延續(xù)性動(dòng)詞

die → be dead

borrow → keep

buy/catch → have

get up → be up

come → be in

finish → be over

leaver → be away

open → be open

close → be closed

begin → be on

become interested in → be interested in

有人可能會(huì)問：一般過(guò)去時(shí)和現(xiàn)在完成時(shí)所表示的動(dòng)作都發(fā)生在過(guò)去，那么這兩種時(shí)態(tài)有什么區(qū)別呢?

☆答：①一般過(guò)去時(shí)與具體的表示過(guò)去時(shí)間狀語(yǔ)如：yesterday連用;強(qiáng)調(diào)動(dòng)作在過(guò)去發(fā)生，與現(xiàn)在無(wú)關(guān)。

②現(xiàn)在完成時(shí)與自已的特征詞連用，強(qiáng)調(diào)過(guò)去發(fā)生的動(dòng)作對(duì)現(xiàn)在的影響或過(guò)去開始發(fā)生一直持續(xù)到現(xiàn)在的動(dòng)作。

例： He saw the film last night. (過(guò)去時(shí)，表示他昨晚看過(guò)那部電影了，現(xiàn)在不知還要不要再看一次)

He has (ever) seen the film before.(現(xiàn)在\完成時(shí)，表時(shí)他已看過(guò)那部電影，現(xiàn)在不想再看了)

鞏固練習(xí)：

I.按要求轉(zhuǎn)換下列各句，每空一詞。

1、He has already finished his homework.(改為否定句)

He _______ finished his homework ________.

2.They have found the lost books already.(改為一般疑問句，并作否定回答)

______ they _______ the lost books _______?No，they________.

3.Julia has not got home from school yet.(改為肯定句)

Julia ______ _______ ________ home from school .

4.You have never been to Shanghai before，_________ _________ ?(改為反意疑問句)

5. He’s gone to Beijing, ______ ______?(改為反意疑問句)

6.Mr Wang began to teach English in this school in 1999.(改為同義句)

Mr Wang _________ _________ English in this school since 1999.

7. He hasn’t left home for 3 days.(同義句)

He _____ ______ ______ home for 3 days.

8. They have lived here since 3 years ago. (對(duì)劃線提問)

II.選擇正確答案。

( )1.—Who is Mary ?

—____?I saw you talking with her at the meeting .

A.Don't you meet her yet

B.Didn't you met her yet

C.Haven't you met her yet

D.Hadn't you met her yet

( )2.—How do you like Beijing ，Mr Black?

—Oh ，I ____ such a beautiful city .

A.don't visit

B.didn't visit

C.haven't visited

D.hadn't visited

( )3.The old people ____ lonely at all since we began to visit them once a week.

A.don't feel

B.hasn't felt

C.haven't felt

D.didn't feel

( ) 4.We have lived here ____ five years ago.

A.when

B.since

C.before

D.after