8B Unit1導(dǎo)學(xué)案及教案1
the train has arrived.火車到了。
have you joined the computer group? 你加入電腦小組了嗎？
b. 終止性動詞表示的動作極其短暫，不能持續(xù)。因此，不可與表示一段時間的狀語連用(只限肯定式)。如：
(1) 他死了三年了。 誤：he has died for three years.
正：he has been dead for three years. 正：he died three years ago.
正：it is three years since he died. 正：three years has passed since he died.
(2) 他來這兒五天了。 誤：he has come here for five days.
正：he has been here for five days. 正：he came here five days ago.
正：it is five days since he came here. 正：five days has passed since he came here.
(1)、(2)句中的die、come為終止性動詞，不能與表示"段時間"的狀語連用。那么，應(yīng)如何正確表達(dá)呢？可以采用下面的四種方法：
(1) 將句中終止性動詞轉(zhuǎn)換為相應(yīng)的延續(xù)性動詞，如上面兩例中的第一種正確表達(dá)方式。下面列舉幾例：leave→be away from, borrow→keep, buy→have, begin/start→be on, die→be dead, move to→live in, finish→be over, join→be in/be a member of, open sth.→keep sth. open, fall ill→be ill, get up→be up, catch a cold→have a cold。
(2) 將句中表示"段時間"的狀語改為表示過去確定時間的狀語，如下面兩例中的第二種正確表達(dá)方式。
(3) 用句型"it is+段時間+since..."表達(dá)原意，如上面兩例中的第三種正確表達(dá)方式。
(4) 用句型"時間+has passed+since..."表達(dá)原意，如上兩例中的第四種正確表達(dá)方式。
3. 終止性動詞可用于現(xiàn)在完成時否定式中，成為可以延續(xù)的狀態(tài)，因而可與表示一段時間的狀語連用。如： he hasn’t left here since 1986. i haven’t heard from my father for two weeks.
4. 終止性動詞的否定式與until/till連用，構(gòu)成"not+終止性動詞+until/till ..."的句型，意為"直到……才……"。
如：you can’t leave here until i arrive.直到我到了，你才能離開這里。
i will not go to bed until i finish drawing the picture tonight.
今天晚上直到我畫完畫，我才上床睡覺。
5. 終止性動詞可以用于when引導(dǎo)的時間狀語從句中，但不可以用于while引導(dǎo)的時間狀語從句中。when表示的時間是"點時間"(從句謂語動詞用終止性動詞)，也可以是"段時間"(從句謂語動詞用延續(xù)性動詞)。而while表示的是一個較長的時間或過程，從句謂語動詞用延續(xù)性動詞。如：when we reached london, it was twelve o’clock. (reach為終止性動詞)
please look after my daughter while/when we are away. (be away為延續(xù)性動詞短語)
6.終止性動詞完成時不可與how long連用(只限于肯定式)。如：
誤：how long have you come here? 正：how long have you been here?
正：when did you come here?