《Language in use》Help PPT課件4
祈使句
此類祈使句喑含的主語是you，但通常省略。句首或句末有時(shí)加please，還可以加上稱呼語，用逗號(hào)與句子主體隔開。
祈使句表達(dá)說話人對(duì)對(duì)方的叮囑、勸告、希望、禁止、建議、請(qǐng)求或命令等。祈使句一 般以動(dòng)詞原形開頭，無時(shí)態(tài)和數(shù)的變化。
▲1. 動(dòng)詞原形構(gòu)成的祈使句
肯定形式
Do型，即動(dòng)詞原形（+賓語）+其他
Be型，即Be+表語（名詞或形容詞）+其他
否定形式：動(dòng)詞原形前加don't，也可以用否定副詞never開頭。
Have a nice day! 祝你度過美好的一天！
Don’t waste your time! 別浪費(fèi)時(shí)間 了！
Never be late again! 再也不要遲到 了！
Come this way please ! 請(qǐng)走這邊。
Please be quiet, boys! 男孩們，請(qǐng)安靜！
Make sure he’s warm. 確保他不受涼。
Don’t use the lift. 不要使用電梯。
... ... ...
▲2. let’s構(gòu)成的祈使句
這類祈使句往往用于提出建議。
肯定結(jié)構(gòu)：Let+賓語+動(dòng)原+其他
否定結(jié)構(gòu)：Don't let +賓語+動(dòng)原+其他
Let+賓語+not+動(dòng)原+其他
▲3. 無動(dòng)詞祈使句
祈使句還可用名詞、形容詞、副詞以及以no開頭的短語充當(dāng)。
... ... ...
情態(tài)動(dòng)詞must, can, could表推測(cè)
▲用法區(qū)別
must
表推測(cè)時(shí)常用在肯定句中，語氣較為肯定，此時(shí)must可以翻譯成“一定；準(zhǔn)是”。
can
表推測(cè)時(shí)常用在否定句或疑問句中，是有把握的否定推測(cè)，意為“不可能”。
could
可以用于肯定句、否定句或疑問句中，也可以表示過去的可能性，表示可能發(fā)生，程度比can弱。
請(qǐng)仔細(xì)對(duì)比下列一組句子
Who sent the present? Can it be your brother?
是誰送來的禮物�。繒�(huì)是你哥哥嗎？ （詢問可能性）
It must be your brother. I saw him in your room just now.
肯定是你哥哥，我剛才看見他在 你的房間里。
（語氣強(qiáng)烈，表示非�？隙ǎ�
It can't be my brother. He is still in France.
不可能是我哥哥，他還在法國(guó)呢。（表示不可能）
It could be your brother. He said he might come back.
可能是你哥哥。他說過他可能會(huì)回來。（表示猜測(cè)可能）
... ... ...
Exercises
1. Complete the sentences with could, must or mustn’t.
keep out意為“留在外面；置身......之外”。
1.It is dangerous. You ______keep out!
2.These stairs are not safe. You _______use them.
3.The rocks are falling down. You _____get hit.
4.The river is too deep. You _______swim in it.
5.Betty _____know what to do , because she did some basic medical training.
2. Underline the correct words to complete the first aid instructions.
1 Get / Do not get medical help immediately.
2 Ask / Do not ask them where the pain is.
3 Lift / Do not lift them because you may drop them.
4 Keep / Do not keep them warm.
... ... ...
by warning them that a tsunami...
by意思是“通過；以（某種方式）”，后面常跟名詞，代詞，V-ing形式，表示通過某種方式、手段等。提問時(shí)用how。
The old man makes his living by selling newspapers.
by的其他幾種用法：
1、表示方位“在......旁邊”。He sat down by the door.
2、表示時(shí)間“在......之前”。Can you finish the work by 5 o'clock.
3、表示交通方式“搭乘”。I go to school by bike.
4、by固定搭配。by the way順便說一下 by oneself獨(dú)自一人
... ... ...
（中考鏈接）
Parents enjoy any progress their children have made and will feel____them.
A. angry with B. interested in
C. proud of D. worried about
Work in groups. Choose an accident from the list in Activity 8 and give instructions about what to do.
When there is School accident…
First…
Second…
Third…
關(guān)鍵詞：《Language in use》教學(xué)課件，外研版八年級(jí)上冊(cè)英語課件，八年級(jí)英語幻燈片課件下載，《Language in use》PPT課件下載，.ppt格式
