將來完成時概念：
將來完成時用來表示在將來某一時間以前已經(jīng)完成或一直持續(xù)的動作。經(jīng)常與before+將來時間或by+將來時間連用，也可與before或by the time引導(dǎo)的現(xiàn)在時的從句連用。
將來完成時的構(gòu)成與用法：
（一）構(gòu)成：will/shall have+過去分詞：
如：We hope it will have stopped raining before we set off for the picnic. 我們希望在出發(fā)去野餐以前雨就已經(jīng)停了。
I'll have done all the work by the time you are back this evening. 你們今晚回來的時候我就將做完所有的工作了。
（二）用法：
1、表示在將來某一時刻將完成或在另一個未來的動作發(fā)生之前已經(jīng)完成的動作。
注意：常與將來完成時連用的時間狀語有：
�、賐y(the time/the end of)+表示將來時間的短語和句子；
②before(the end of)+表示將來時間的詞語或句子；
③when, after等加上表示將來動作的句子等。
例如：By the year 2050, scientists probably will have discovered a cure for cancer.
到2050年，科學(xué)家們可能已經(jīng)找到治愈癌癥的方法了。
By the time you arrive in London, we will have been staying in Europe for two weeks.
等你到達倫敦的時候，我們將已經(jīng)在歐洲呆了兩星期了。
2、在時間從句和條件從句中，現(xiàn)在完成時可以代替將來完成時，表示將來某時業(yè)已完成的動作。
例如：You'll get to like the subject after you have studied it for some time.
在學(xué)習(xí)這個學(xué)科一段時間之后，你就會喜歡它的。
I'll go and see the exhibition as soon as I have finished my work. 我一做完作業(yè)就去看展覽。
3、將來完成時還可以表示"可能性"，或"設(shè)想"。
例如：It's five o'clock, they will have arrived home by now. 已經(jīng)五點鐘了，他們現(xiàn)在應(yīng)該已經(jīng)到家了。
將來完成時與一般將來時的比較：
1、有具體的時間狀語要用一般將來時。
如：Mr Smith will return home on the first Sunday next month. 史密斯先生將于下月的第一個星期日回家。
2、將來完成時的時間狀語一般用介詞by引入。
如：Mr Smith will have returned home by next month. 到下個月史密斯先生將已回到家了。
典例精析：
1、They_____on the program for almost one week before I joined them, and now we_____it as no good results have come out so far.
A. had been working; are still working
B. had worked; were still working
C. have been working; have worked
D. have worked; are still working
答案：A。
解析：不難看出第一空的動作發(fā)生在I joined them以前，且持續(xù)了一個周，應(yīng)該用過去完成進行時；and now說明下面的動作仍在進行之中，應(yīng)該用現(xiàn)在進行時。故選A。
2、Father_____for London on business up on my arrival, so I didn't see him.
A.has left
B.left
C.was leaving
D.had left
答案：D。
解析：由"I didn't see him"可知父親在我回來以前已經(jīng)離開，動作發(fā)生在過去某個動作以前，故選用過去完成時。
3、The policeman's attention was suddenly caught by a small box which_____placed under the Minister's car.
A. has been
B. had been
C. was being
D. would be
答案：B。