be to do的正確用法
在英語裏，“ be + to do ”結構可用來表示將來時間，下面是本站小編整理的一些關於be to do的正確用法，歡迎大家閱讀！
be to do sth 的正確用法
1、be + to do 表示“想，打算”，相當於intend, want。
If we are to be there before ten, we’ll have to go now.
如果我們要在十點前到，我們現在就得走。
以下是be to do sth. 作情態助動詞的用法。
2、be + to do 表示按計劃或安排要做的事。
When are you to leave for home?
你什麼時候回家?
She is to be married next month.
她將於下個月結婚。
The Queen is to visit Japan in a week’s time.
女王將於一週後訪問日本。
這種結構也可用於過去。was / were to do sth. 表示曾經計劃要做的事，但並說明計劃是否被執行了，所以也可表示曾經計劃但未有實現的事。例如：
I felt nervous because I was soon to leave home for the first time.
我感到很緊張，因爲我很快就要首次離開家了。
They said goodbye, little knowing that they were never to meet again.
他們告了別，不知道以後再也不會見面了。
We were to have told you, but you were not in.
我們本來想告訴你的，但是你不在家。
3、be + to do 表示“可以，可能”，相當於may, can。
The news is to be found in the evening paper.
這條消息可以在晚報上見到。
Such people are to be found everywhere.
這種人到處都有。
She is nowhere to be found.
在哪裏也找不着她。
4、be + to do 表示“應該”，相當於should, ought to。
You are to report to the police.
你應該報警。
What is to be done?
應該怎麼辦呢?
5、be + to do 表示“必須”，相當於must, have to。
The letter is to be handed to him in person.
這封信必須親手交給他。
You are to do your homework before you watch TV.
看電視之前你得先做完作業。
6、be + to do 用於否定句，表示“禁止”，相當於mustn’t。
The books in this room are not to be taken outside.
這個室內的書籍不得帶出室外。
You are not to smoke in the reading-room.
你不可以在閱覽室裏吸菸。
7、be + to do 用於第一人稱疑問句，表示徵求對方意見。
Am I to go on with the work?
要我繼續完成這項工作嗎?
What are we to do next?
我們下一步該怎麼辦?
8、在虛擬語氣中，不論什麼人稱都用were to do sth. 表示對未來的假設。
If I were to tell you that I killed him, would you believe me?
要是我告訴你是我殺了他，你會相信嗎?
Even if the sun were to rise in the west, I would never do such a thing.
即使太陽從西邊出來，我也決不做這種事。
9、還有兩個常用的 be to do sth. 結構：be to blame(該受責備，對某壞事應負責任)，be to let(待出租)。兩種結構中，用不定式的主動形式表示被動含義。
Which driver is to blame for the accident?
這事故是哪個司機的責任?
This house is to let.
這房子要出租。
