(一)Do型祈使句,即:动词原形+宾语+其他成分
Listen to the teacher carefully.仔细听老师说。
Open your book.打开书本。
Stop talking!停止讨论。
1.祈使句可以加上称呼语,可放句首或句末,用逗号隔开。
Tom ,turn off the light.汤姆,关一下灯。
Come in,boys !进来,男孩们。
2.无论祈使句是肯定还是否定,后面可以加一个简短疑问句“will you”,使语气变得委婉、客气些。
Give me a hand,will you?帮一下忙,好吗?
Turn on the radio,will you?打开收音机,好吗?
Don't close the window,will you?不要关窗,好吗?
3.祈使句表示请求或客气语气的时候,可以在句首或句尾加上please,如果please放在句末,一定在please前加逗号“,”。
Please open the door.请开门。
Open the door,please.请开门。
(二)Be型祈使句,即:Be+表语(名词/形容词)
Be a good boy.做个好男孩。
Be quiet,please.请安静。
Please be careful.小心一点。
(三)Let型祈使句,即:Let+宾语(名词/人称代词宾格形式me,him,her ...)+动词原形(+其他成分)
Let Tom/Mary/the children be there before ten o'clock.
Let us/me/him/her help the old woman.
Let's go at once.
Let the boy go to school by himself.
1.Let's是Let us的缩写,但是分别有不同意思:
Let's“让我们一起做……”(包括说话者和听话者)
Let us“让我们一起做……”(不包括听话者)
—Mum,it's a sunny day.Let's go to the park.妈妈,今天是个大晴天。让我们一起去公园吧。(和妈妈一起去公园)
—Tom,let's have dinner together.Tom,我们一起吃晚饭吧。(邀请Tom一起吃晚饭)
— Mum,we have no homework today.Let us play football in the park.妈妈,今天我们没有回家作业。让我们去公园踢足球吧。(孩子们请求妈妈允许他们去公园踢足球,妈妈不去。)
— Let us prepare the birthday party for you,Mum.妈妈,让我们帮你准备生日派对吧。
2.Let's和Let us的反义疑问句的构成:
Let's go to the Shanghai History Museum together,shall we?让我们一起去上海历史博物馆,好吗?
Let's go for a walk,shall we?让我们一起散步吧,好吗?
Let us make a model plane,will you?让我们做一会儿模型飞机,好吗?
Let us help you,will you?让我们来帮助你,好吗?
(四)Always和Never 放在句首可以起到强调作用
Always look left then right before you cross the street.过马路前永远先看左边再看右边。
Never answer the phone while driving.绝不要在开车的时候接电话。(注:never=don't,但是never的语气比don't要强烈)
Never talk to your mother like that.永远不要再像那样跟你妈妈说话。
Exercises
13.1 Complete the sentences (根据句子意思和提示,用Let's提出建议)
have a rest go for a drink go and see it
go inside do another exercise ask someone for help
1.I'm thirsty.Let's ________.
2.It's very hot.Let's ________.
3.There's a good film on at the cinema.Let's ________.
4.I need more practice.Let's ________.
5.I'm tired.Let's ________.
6.We're lost.Let's ________.
13.2 Fill in the blanks (用括号内所给动词适当形式填空)
1.Jack,____ (not be)late for school again.
2.____ (not make)any noise!The baby is sleeping.
3.No ____ (smoke)in the restaurant!
4.Let's ____ (play)games together.
5.Let me ____ (try)again.
6.Your voice is too soft.____ (read)aloud,please.
7.____ (be)quick!Or we'll be late for the train.
8.____ (not let)the baby touch the paint.
9.Please ____ (turn on)the television.
10.____ (watch)out!The bus is coming.