be to

be to + 动词原形的最常见的用法是表示计划或安排：

1. The Prime Minister is to visit Budapest. 首相将访问布达佩斯。

2. Their daughter is to be married soon. 他们的女儿很快就要结婚了。

3. Who is to question him? 该由谁来问他?

4. They usually write exact instructions how the music is to be played. 他们通常还要为如何演奏他们的乐曲写出精确的说明。

be to 的过去时 was/were to 则表示过去的计划或安排：

1. It was the last film at the cinema, which was to close the next day. 这是这家电影院上映的最后一部电影，它第二天就要关门了。

2. Then the great day came when he was to march past the palace in the parade(接受检阅的队伍). (全国高考,98-43) 于是那个不平凡的日子到来了,在那一天他要在接受检阅的队伍里通过宫殿。

3. He was to go on stage in the second scene. (同上,91-完形填空) 他应当在第二场登台。

4. On December 27, 1831, a tiny 242-ton ship, the Beagle, left England on a journey that was to last five years. 1831年12月27日，一艘242吨位的小轮船——猎犬号离开英国，开始了将历时5年的航行。

5. After dinner they were to go to a movie. 午饭后他们要去看电影。

be to + 动词原形还可表示指示 (instructions)、命令 (orders) 或要求 (requirements)，通常可译为“应当”“必须”：

1. No one is to leave this building. 谁也不得离开这幢楼房。

2. You are not to smoke in this room. 你不可以在这房间里抽烟。

3. The form is to be filled in and returned within three weeks. (PEU) 请于三周内将表填好并返回。

4. You are to be back by 10 o'clock. (CGEL) (You are required to be..., You must be...) 你必须10点以前回来。

be to + 动词原形亦可用在间接引语中, 表示指示、命令或要求。这时是说话人转述别人的指示、命令或要求。你所提问的句子便属于此种类型。be to 在这里相当于 had to, must, should。

1. The headmaster says you are to come at once. 校长说你必须马上来。

2. The teacher said we had to wait/we were to wait outside. 老师说我们必须/应当在外面

等着。

be to 的过去时形式 was/were to 还可表示纯过去将来时的意义, 见 was/were to do。请分析下面的实例(注意 was/were to have done 表示过去本安排了做某事, 但实际并没有做):

1. This film ____ this Sunday. A. is going to show B. is showing C. is to be shown D. will have been shown

2. The students were told that they ____ at the school gate at 2:00 the following afternoon. A. met B. will meet C. were to meet D. were met

3. The house ____ ready today but as there has been a builders' strike it is still only half finished.

A. is B. was to be C. was D. was to have been

请把下列句子译成中文并指出三个 are to be + v-ed 的含义(参见 some few):

On the subject of reading, Francis Bacon, who lived at about the same time as Shakespeare, wrote these words, “Some books are to be tasted, others to be swallowed, and some few to be chewed and digested.”

连系动词 be 的词义是“是”，其语法作用是把主语与主语补足语（表语）连接起来。当主语补足语为名词或动词不定式时，主语和主语补足语在概念上是等同的：

John is a teacher. John = a teacher

The problem is to find a solution. the problem = to find a solution

《英语语法大全》上列例句中的 be 并不具有这些特点,不应看作是连系动词。其实,其中的 be(am/is/are, was/were) to 是一个独立词汇单位,具有情态含义。G. N. Leech 在 Meaning and the English Verb 中将它放在 the modal auxiliaries(情态助动词)一章中进行讨论。R. Quirk 等人则把它叫做 modal idiom(情态习语)。许多英英词典和英语语法著作都把 be to 列为独立的词条进行讨论,例如,OGEG, CIDE, NODE 等。

如果不把连系动词 be 与情态习语 be to 中的 be 加以区分,那就无法辨别下列句子的语义和语法结构:

The committee is to find a solution. 委员会将会找到解决方法。

The problem is to find a solution. 问题是要找到一个解决方法。

在第一个句子里 is to 是情态习语, find 是谓语组成成分; 在第二个句子里, is 是连系动词, 动词不定式 to find a solution 是主语补足语(表语)。

be to(+不定式)结构具有许多含义和用法。你所引用的句子里的 be to 结构是表示

“指示、命令或要求”。例如：

1. You are to be back by 10 o'clock.

(You are required to be..., you must be...) (CGEL) 你必须 10 点以前回来。

2. He is to stay here till we return. 他必须留在这里直到我们返回来。

3. Fache's eyes shone white. 'That, monsieur, is precisely the question you are here to answer.' (Dan Brown, The Da Vinci Code) 法希的眼睛发着白光。“先生，那正是你今晚到这儿来要回答的问题。”(《达·芬奇密码》)

我们已经讲过,充当主语补语的动词不定式,在语义上一般能够与主语划上个等号: The problem is to find a solution.

the problem = to find a solution

在你所提问的句子里，主语 this room 与 to let 在语义上是绝不能划等号的。因此，单从这一点就可以否定 to let 充当主语补语的说法。那么，to let 到底是什么成分呢？它是谓语动词的组成部分。原来，上句中的 is 并不是连系动词，而是 be to 这一助动词的组成部分。be to 在这里是表示“计划”“安排”的意思，见 blame 和 be to $^{2}$ 。

上面句子里的 be to(was to) 结构并不是“表示未来可能发生的动作”，而是表示“可能”，见 be to $^{4}$ 。

He ran to the opening and looked over the edge. Langdon was nowhere to be seen. (Dan Brown, The Da Vinci Code) 他跑到玻璃缺口处，顶着窗沿向下望去，兰登已经无影无踪了。(《达·芬奇密码》)

was/were to do 有时表示过去曾经计划要做的事,或者过去应当做的事,而且从现在角度来看已经实现了。例如：

1. I felt nervous because I was soon to leave home for the first time. (PEU) 我感到紧张,因为我很快就要初次离开家了。

2. The clergy were to receive salaries from the state. (Hazen) 牧师从国家领取工资。

was/were to have done 则表示“本打算”“本计划”或“本应当”做的事而没有做成或没有发生。例如：

1. I was to have seen him last Wednesday but he did not come. (Yeats) 我本应当上周三就见到他,但是他没来。

2. We were to have been married last year. (GPU) 我们本应当去年就结婚。请做下面的英语试题：

3. "Have you been to Mexico?" "No, I ____ last year, but Dad wouldn't let me."

A. was to have gone B. were to go C. was gone D. went(Michigan)

2. The second book was ____ by August 1952, but two years later, the end was still nowhere in sight. A. completed B. to have completed C. to complete D. to have been completed(全国六级,95.6-42)

3. I ____ writing the paper as scheduled, but my mother's illness interfered. I hope you will excuse me. A. am to have finished B. was to have finished C. was to finish D. ought to finish(全国英语专业四级,93-54)

4. I was to have made a speech if ____. A. I was not called away B. nobody would have called me away C. I had not been called away D. nobody called me away(全国英语专业四级,97-51)

5. Linda was ____ the experiment a month ago but she changed her mind at the last minute. A. to start B. to have started C. to be starting D. to have been starting(全国英语专业四级,07-55)