表示“应该”和“必须”的情态助动词 should, ought to, have to 与must
（1）表示不可逃避的义务或表示“必须”的must。must通常只用于现在时和将来时，其他时态则用 have to代替。have to比must往往更强调客观的要求或外在的原因： destination是什么意思
In the play, she must appear in a bright red dress and long black stockings.
演出时她必须穿一条鲜红色的裙子和黑色的长筒袜。
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Last year in another play, she had to wear short socks and a bright, orange-coloured dress.
去年在演另一个剧时，她不得不穿短袜和一件鲜艳的橘红色的衣服。
（2）should 和 ought to都可译为“应该”，表示义务、责任或某个正确的行为。ought to比 should语气略强些，多用于肯定句；疑问句与否定结构则多用 should。与它们相比， must和 have to 的语气要强得多，没有选择余地：
must和have to表示“必须”，而should和ought to表示“责任”、“义务”或是“一个正确的行动”。试比较：
I can’t go to the cinema tonight; I must (or have to) write some letters.
今晚我不能去看电影，我必须写几封信。（我没有选择，我必须而且将会写这些信。）
I should (or ought to) do some work tonight, but I think I shall go to the cinema instead.
今晚我应当做一些工作，不过我想我会去看电影的。（对我来说，正确的做法是工作，但是我选择了去看电影。）
（3）had to表示“过去的必须”，表示过去必须做某事。should be doing(应正在做)，而“should( ought to)+have+过去分词”表示过去应该做（或完成）而没有做的事，我们经常翻译为“本该做…”。
I misd the train, so I had to take a taxi.（我没有选择，只有叫计程车）
I’m sorry I’m late, I should(or ought to) have taken a taxi.（我知道正确的做法应该是叫车来的，但是我没有叫。）
You ought to （should） have been more careful in this experiment. 你当时在做试验时应
该更仔细点。
ought to have done sth, should have done sth表示本应该做某事，而事实上并没有做。否定句表示"不该做某事而做了"。例如：
He ought not to have thrown the old clothes away.他不该把旧衣服扔了。（事实上已扔了。）
Have使役式（The causative）
（1）动词 have除了可以作为助动词构成完成时以外，还可以作为完全动词表示“拥有”或代替 take, eat, receive, experience 等动词（cf. 第18课语法）：
Did you have a good meal?
您吃得好吗？
He has five cars.
他有5辆汽车。
怎么学好日常英语口语
have+名词可以代替普通动词：
They had a nice swim.
他们很畅快地游了泳。
（2）have作为完全动词还可以构成使役式，其形式为： have+名词或宾格代词+动词的过去分词(have sth. Done)。由于have是完全动词，所以其疑问句与否定句由do/did构成。与被动语态相似，使役式着重表示的是对某物（或某人）做了什么而不是某人做了什么。我们经常翻译为“让人来做某事”。试比较：
I’m repairing my car.我在修理自己的汽车。（主动语态）
My car is being repaired.我的汽车正在检修。（被动语态）
英语培训费用I’m having my car repaired.我正在让别人修理我的汽车。（使役式的进行式）
用被动语态或使役式时，我们可能不知道或认为不必指明为我们服务的人是谁。然而，使役式比被动语态更加强调“使”别人为我们服务这一事实。我们要表示让别人为我们做某事
时，通常不用主动语态。让别人给自己理发时，不可说I want to cut my hair而要说 I want to have my hair cut。
I washed my car.(I washed it mylf.)
我洗了车。
努力学习演讲稿
I had my car washed.(Someone el washed it for me.)
我让人洗了车。
I'm going to clean my suit.(I'm going to clean it by mylf.)
我将洗一洗我的西服。
I'm going to have my suit cleaned.(Someone el will do it for me.)
我将把我的西服送出去洗一洗。
He had his hair cut yesterday. naturein
他昨天理了发。
I will have to have my watch repaired.
我将不得不去修表。
Did you have your watch repaired?
你把你的表修好了吗？
I didn't have my watch repaired. resume是什么意思
我没有把表修好。
使役式也可以用以指人：
arrive的用法
While I'm away, I'll have you looked after.
1.I will tell him as soon as he _____ back
A. come B. comes C. will come D. came
2. Mary _____ on shoes when she ____ them.
A. tries…buys B. tries… buies C. trys… buys D. trys… buies
3. The girl often ______ cold when she ______.
A. cathcs…dances B. catches… dances C. catchs…dancees D. catches… dancee
4. _____ he ____ himlf there? No, I don't think so.
A. Do…enjoy B. Does… enjoies C. Does… enjoys D. Does…enjoy
5. _____ your teacher ____ from them very often? Certainly.
A. Do…hear B. Does…hear C. Do… receive D. receive
6. _____ your mother _____ some cleaning on Sundays?
A. Does…does B. Do…does C. Does…do D. Do… do
7. _____ Tom _____to work hard to help his family ? Yes, he _____.
A. Has… x…does B. Has…x…does C. Does…has…has D. Does… have…does
besure 8. Which teacher _____ lessons to you every day ?
A. does …gives B. does… give C. do… give D. gives
9. Smith does not go fishing on weekdays, ____? _____ , he does.
A. does he…No B. does he…Yes C. doesn't he…No D. doesn't he…Yes
10.Mr Black often _____ fishing on Sundays, _____ he ?
A. goes…doesn't B. goes…isn't C. doesn't go…does D. doesn't go…is
11.He usually _____ TV on Sunday evening.
A. watch B. watches C. watching D. is watching
12. We'll go to play with snow if it ______ tomorrow.
A. snow B. snows C. will snow D. snowed
13. Neither I nor he ______ French.
A. speak B. doesn't speak C. speaks D. doesn't speak
14. Nobody ______ how to run this machines.
A . know B. have known C. knows D. is knowing
男警察和女警察们15. The Young Pioneer _____ water for the old man every day.
A. carry B. bring C. takes D. carries
