表示按计划、安排即将发生的动作。例如： There’s to be an investigation. I am to have tea with Betty this afternoon. 这一结构常见于报纸和广播，用以宣布官方的计划或决定。例如： The Queen is to visit Japan next year. 二是表示命令、禁止或可能性等。例如： You are to stand here. Do you understand? Tell her she’s not to be back late. 一般现在时也可表达将来时间，常见于条件状 语和时间状语从句。例如： If she comes, I’ll tell her all about it. Wait here till the meeting is over. It won’t be long before the rain stops.
begin 在这组词中最常用，泛指开始做某事。但口语中近年来start用得较多。 The band began to play joyful music.乐队开始演奏欢快的音乐。
commence 比begin用法正式。在宗教或其它仪式及军事用语中人们倾向用commence. The officer ordered the soldiers to commence the attack.军官命令士兵开始进攻。
initiate 指进程中的第一步，与何时停止或结束没有关系。 The government has initiated a new reform program.政府启动了新的改革方案。
launch 指开始或着手一项活动、计划等大规模或声势浩大的行动，行动前或行动中有一定的宣传鼓动。 The company will launch an advertising compaign to introduce its new product.那个公司要发起广告攻势推出自己的新产品。
Start 与stop构成反义用法，指从一特定地点出发，由静止或等待状态开始做某事。在口语中常可代替begin。 They started operations at once.他们马上开始行动。
全真模拟试题 1. ____ in the past, at the moment it is a favorite choice for wedding gown. A. Unpopular has as white been B. White has been as unpopular C. Unpopular has been as white D. Unpopular as white has been 2. ____ for a long time, the fields are all dried up . A. There has been no rain B. Having no rain C. There having been no rain D. There being no rain 3. The millions of calculations involved, ____ by ha nd, would have lost all practical value by the time they were finished. A. had they been done B. they had been done C. having been done D. they were done 4. Televisions enable us to see things happen almost at the exact moment ____. A. which they are happening B. they are happening C. which they happen D. they have happened 5. ____ me most was that the young boy who had lost both arms in an accident could handle a pen with his feet. A. That amazed B. It amazed C. Which amazed D. What amazed 6. Although she wrote a lot of short stories and poems when she was very young, ____ she was twentyfive. A. her first real success did not come until B. her real first success came until not C. since her first real success did not come until D. not until her first real success 7. You should know better than ____ your little sis ter at home by herself. A. to leave B. leaving C. to have left D. left 8. As the train will not leave until one hour later, we ____ grab a bite at the snack bar. A. may well B. just as well C. might as well D. as well 9. She resorted to ____ when she had no money to buy foods for her children. A. have stolen B. steal C. stole D. stealing 10. The boy has admitted to ____ the window while pl aying football yesterday. A. breaking B. having been broken C. break D. be breaking