現(xiàn)在完成時用法——持續(xù)性用法(肯定句，疑問句中謂語動詞必須是延續(xù)性動詞)：表示過去已經開始，持續(xù)到現(xiàn)在的動作或狀態(tài)。此時常與“for +一段時間?或“since+過去的點時間或從句(從句用一般過去時)以及so far(到目前為止)等時間狀語連用。

　　for + 段時間

　　since +點時間

　　實例：

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

　　= 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 .

　　自從到這個城市以來，王先生一直在這家工廠工作。

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

　　自從五年前以來她就在這個學校。

　　注意：①在這類句子的肯定句和疑問句中謂語動詞必須用延續(xù)性動詞。短暫性動詞由于動作不能持續(xù)，故不能與for(達到;累計)或since(自從。。。到現(xiàn)在)引出的時間狀語連用。

　　②對for和since引導的時間狀語提問要用How long

　　1) 他入團兩年了。

　　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) ▲部分短暫性動詞與之對應的延續(xù)性動詞：

　　短暫性動詞 延續(xù)性動詞

　　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

　　有人可能會問：一般過去時和現(xiàn)在完成時所表示的動作都發(fā)生在過去，那么這兩種時態(tài)有什么區(qū)別呢?

　　☆答：①一般過去時與具體的表示過去時間狀語如：yesterday連用;強調動作在過去發(fā)生，與現(xiàn)在無關。

　?、诂F(xiàn)在完成時與自已的特征詞連用，強調過去發(fā)生的動作對現(xiàn)在的影響或過去開始發(fā)生一直持續(xù)到現(xiàn)在的動作。

　　例： He saw the film last night. (過去時，表示他昨晚看過那部電影了，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，表時他已看過那部電影，現(xiàn)在不想再看了)