英語語法大全|現在完成時的結構和用法

（一）基本結構

現在完成時的句子結構一般為：

主語+have/has+過去分詞+其他成分

如：

We have already had lunch.

He has been away for a week.

（二）主要用法

1、表示過去發生并且已經完成的動作對現在造成的影響或結果。此時，常和謂語動詞一起使用的副詞有already、just、never、ever、yet等。如：

They have already come back from the museum.

She has already finished her homework.

2、表示過去發生的動作持續到現在，并且有可能會繼續持續下去。此時，常和謂語動詞一起使用的標志性詞語主要有for和since，而且此時的謂語動詞往往是持續性動詞（如stay、keep、wait等）。如：

I have lived here for ten years.

He has kept the clavichord since thirty years ago.

3、表示從過去某一時間到說話時這段時間中反復發生的動作。此時，常和謂語動詞一起使用的主要是表頻度的副詞often、always、seldom、never等，以及表次數的單詞或短語（如once、twice、three times）。如：

You have never listened to me like this before.

She has ever been to France.

They have visited the Summer Palace many times.

（三）動詞的過去分詞

1、規則變化

其變化規則與動詞的一般過去時基本相同，主要是在詞尾加-ed或-d。具體的有：

1）直接加-ed。如：worked、played。

2）以不發音的e結尾的動詞后加-d。如：lived、danced。

3）以輔音字母加y結尾的動詞后改y為i，再加-ed。如：studied、cried。

4）以重讀閉音節結尾的動詞后，雙寫最后一個輔音字母再加-ed。如：stopped、patted。

2、不規則變化

如果結合動詞的過去式，動詞的過去分詞的不規則變化中，又有一些相對的規則現象。如：

1）AAA型。如：put put put；read read read。其中，read的過去式和過去分詞雖然拼寫時一樣的，但其發音與原形不同，ea不再讀作[i?]，而是[e]。

2）AAB型。如：beat beat beaten 

3）ABB型。如：keep kept kept；sit sat sat

4）ABC型。如：lie lay lain；drink drank drunk

5）ABA型。如：run ran run；come came come

（四）標志性詞語

1、副詞already、just、never、ever、yet等。如：

She hasn't arrived in Scotland yet.

They have just left for Shanghai.

2、for和since。for+一段時間，since+具體時間。如：

He has learned Italian for five months.

He has learned Italian since five months ago.

3、so far和up to/till now。表示“迄今為止”。如：

So far, no one has heard any news about her.

She has read fifty books up to now.

4、recently、lately等表示“最近；最新”的副詞和形容詞。如：

I've met her on several occasions recently.

He hasn't had enough sleep lately.

5、in the past/last+一段時間，表示“在過去的...時間里”。如：

In the past few years, new buildings have sprung up all over Beijing.

He had aged rapidly in the last few months.

6、次數。如：

I've tried many times, but there's no way.

He has been there at least twice.

（五）have been to/have gone to/have been in

1、have been to

表示“去過已回”。句子主語就在現場。如：

They have been to Rome many times.

She has been to Shanghai more than once.

2、have gone to

表示“去了未回”。句子主語不在現場。如：

Jerry has gone to Hangzhou.

Mary has gone to Finland.

3、have been in

表示“一直待在某地”。如：

We have been in Beijing for five weeks.

They have been in China since 2012.

（六）短暫性動詞和延續性動詞

所謂短暫性動詞主要是指一旦發生馬上就結束的動作，也叫瞬間動詞，如die、marry、leave等。而延續性動詞主要是指可以一直持續進行的動作，也叫持續性動詞，如learn、live、talk等。

兩類動詞都可以用于現在完成時，但是短暫性動詞不能與表示一段時間的時間狀語連用。此時，需要把短暫性動詞改為相應的表狀態的動詞或短語。如：

錯誤：He has died for ten years.

正確：He has been dead for ten years.

錯誤：She has married him since five years ago.

正確：She has been married to him since five years ago.

（七）句型轉換

因為“have/has done”中的have/has是助動詞，所以在進行句型轉換中要注意不需要再另外借助助動詞do/did/does，而是直接借用have/has。如：

肯定句：He has lived here for the last few years.

否定句：He hasn't lived here for the last few years.

一般疑問句：Has he lived here for the last few years?

特殊疑問句：How long has he lived here?  （劃線部分為for the last few years）