禁止和警告
我们要让别人注意某种危险或不许涉足某事，就应该善意地进行禁止，或提出警告。那么，怎样表达呢？
I．Daily Expressions in Communication（日常交际用语）
a．You can't／mustn't．．．．你不能／不可以……。
If you．．．，you'll．．．．如果你……，你就会……。
b．Take care！留神／当心！
Be careful！小心！
II．Conversations（会话实例）
A
Mother：Betty，what's the time？
Betty：Oh，it's a quarter past seven．
Mother：Be careful not to be late for school①．Hurry up！
Betty：Yes，Mum．I'm going．Goodbye，Mum ．
Mother：Bye-bye．Oh，be careful when you cross the road．There's a lot of traffic．
Mother：Yes，I know ．Don't worry．
B
Mike：Jack，whose bike are you riding？It's so nice．
Jack：It's my new bike．Mother bought it for m e yesterday．Oh！
Mike：Oh，be careful②！You nearly fell off your bike．
Jack：Thanks．I'll be more careful．
Mike：Hey，look out！There's a car coming round the corner．You mustn't ride so fast③．It's very dangerous．
Jack：You're quite right④．I'll really be more careful and not ride too fast．
C
Mother：Bob，are you full？
Bob：No，Mum．I'm still hungry．Can I have another cake？
Mother：OK．Here you are．
Bob：Can you pass me another egg and some roast fish，meat and chicken，
please？
Mother：Oh，dear！What a big breakfast⑤you are having！You shouldn't
eat so much food at a time．
Bob：But it's very delicious．And I'm still hungry．
Mother：Don't be foolish，Bob．You've had enough．You mustn't eat too
much food．If you eat too much，you'll be even fatter，and you'll
be ill，too⑥．And then you must see a doctor．
Bob：W ell，I'm stopping．I'll have it for lunch．
D
Yang Fang：Alas！I can't work out this maths problem ．
Mary：Let m e have a look．Oh，I can help you．
Mother：Fangfang，supper's ready．Ask Mary to have supper with us．
Hurry up！
Yang Fang：Don't shout at m e！I'm very busy．I hate to be disturbed when I am busy．
Mother：What did you say，Yang Fang！
Mary：Yang Fang，you can't talk to your mother like that．It's not polite at all．Aunt Li，please don't be angry with her．
Yang Fang：Mum ，I'm very sorry．I was vexed about the m aths problem ．
It was my fault．I won't do that again．
Mother：W ell，I'll forgive you this time．Don’t behave like that any more．Let's have supper now ．
E
Yang Fang：I've finished doing my exercises at last．
Mary：I have only one left．Oh，my pencil is broken．May I use your knife．
Yang Fang：Certainly．Here you are．The knife is sharp．Be careful with your fingers．
Mary：Thank you．I'll be very careful．Here's your knife．Thanks．
Yang Fang：That's OK．
Mary：I've also finished mine．Oh，it's nine o'clock now．I'm afraid I must be going．
Yang Fang：Let me see you to the door⑦then．It's dark here．Watch your steps．
Mary：Thank you．See you tomorrow．Good night！
Yang Fang：Good night！
III．New Words and Phrases（生词和词组）
IV．Notes（注释）
①Be careful not to do sth．常用于提醒别人不要做某事，是比较客气的警告，意为“小心别……。”又如：Be careful not to hurt yourself．小心别伤着自己。类似说法还有：You should be careful of your head．你应该小心点，别撞着头。You must be careful with dogs．你应该小心狗。
②在有可能出现危险的情况下，我们应该提醒对方注意：Be careful！意为“小心！”意思相近的类似警告用语还有：Look out！／Take care！／Watch out！／Watch it！／Mind out！等。
③You mustn't．．．．表示的往往是明令禁止不准做的事情，其态度非常严肃、坚决，意为“你不可以……。”又如：You mustn't smoke near the oil depot．你不许在油库附近吸烟。
④对别人的禁止或警告应作出回答，可用Thanks．／Thank you．／Yes．／You're quite right．等表示感谢、接受或同意。
⑤多数西方人早饭吃得不多：一杯咖啡或茶、两片面包或烤面包便完了，有的人还吃点香肠或一个鸡蛋。但也有人吃得较多，除饮料外，还要吃炒菜等，这就叫 a big breakfast，“一顿量多的早餐”。早餐
时只吃很少一点东西，则叫a light breakfast，“一顿量少的早餐”。
⑥If you．．．，you'll．．．．是一种有条件的禁止或警告，含有威胁、恐吓的意味，意为“假如你……，你就会……。”又如：If you ride a bike too fast，you'll have an accident．假如你骑车骑得太快，你就会出事。
⑦see sb．to the door意为“把某人送到门口”。将see换成walk，意思不变。应当了解英美人送客的习惯与中国人不同，他们一般只送到门口，而中国人曾“十里长亭相送”，甚至有“送君千里，终须一别”之说。英美人送客时，主人不说Go slowly．（慢走。）之类的话，客人也不说Don't come any farther．（别送了。）或者Stay where you are．（请留步。）之类的话。当然，如果客人对回去的路不太熟悉，希望主人送一程，应主动提出，主人一般会欣然应允。
