1.英語中情態動詞前后應該跟什么
一般句式:主語+謂語+賓語,情態動詞只能充當謂語!eg(例如):I can speak English.例句中can為情態動詞,前面所接的就是主語 I (人),當然也可接某物或者某事,有一點,主語(也就是情態動詞前的)只能是名詞、動名詞(動詞+ing)、動詞不定式(To+動詞)!●那情態動詞后面接的就簡單了,直接加動詞原形,如上例中的speak,就沒加任何變化!●句型:主語+情態動詞+動詞原形eg:He(主語) can(情態) play(動原) the basketball.。
2.英語中情態動詞講解和練習題
一、情態動詞的語法特征(1)情態動詞不能表示正在發生或已經發生的事情,只表示期待或估計某事的發生.(2)情態動詞 除ought 和have 外,后面只能接不帶to 的不定式.(3)情態動詞沒有人稱,數的變化,即情態動詞第三人稱單數不加-s.(4)情態動詞沒有非謂語形式,即沒有不定式、分詞、動名詞等形式. 高考重點要求:1、情態動詞的基本用法2、情態動詞表示推測的語義差別3、情態動詞后接不定式完成體的不同意義4、虛擬語氣中情態動詞的用法 知識點掃描一、情態動詞 (一)情態動詞種類1. can表示體力或腦力方面的“能力”、“技能”或根據客觀條件能做某種動作的“可能性”, 但表示人的體力或智力的具體動作時須用 be able to .He was able to do that without any help.他不需要任何幫助就能完成這項工作.2. may表示“允許,可以”,相當于be allowed to .may或might可和as well連用,表示“建議”,譯為“還是……的為好”You may as well keep a certain distance from that mad man. 你們還是離那瘋子遠點為好.You might as well go home now.你還是現在回家為好.3. must表示“必須”或“應當”、“一定”.4. have to 加動詞原形,表示“不得不”,“必須”,它比must更強調客觀.Tom had to work into the deep night every day to earn a living. 湯姆為了生計每天都得工作到深夜.5. should 表示“勸告”,“建議”或“義務”時,譯作“應當”,或表示“預測”和“可能”.He should take care of his parents as they are old enough not to live on themselves. 由于父母親老了,不能自理,他應當照顧他們.He should be there now. 他應該在那兒.should have done在虛擬語氣中表示“責備或后悔”.6. ought ,只有一種形式,且ought后必須加to,然后跟接動詞原形表示“有義務”或“必要”做某事,譯為“應當,應該”.7. dare 可以用作情態動詞,后面跟不帶to的動詞不定式,這主要用于否定句中,它本身可有現在時第三人稱單數,詞尾加s,它還可以有ing分詞形式(daring)和過去式及ed分詞形式(dared).(二)情態動詞在一般時否定句中的用法can't(cannot) 表示“不可能”, may not 表示“不可以”, mustn't(must not) 表示“一定不要”,“不許可”,needn't (need not) 表示“不必”,dare not +動詞原形表示“不敢”.He can't finish his essay by this time. 現在他不可能寫完論文.He may not sleep now. 他或許現在沒在睡覺.You mustn't criticize her in that way. 你不應那樣批評她.You needn't come tomorrow. 你明天沒必要來了.He dared not meet his fiancée. 他不敢見女朋友.(三)can,may,must三者用法比較can,may,must是三個最重要的情態動詞,其基本句型如下:肯定句:主語+can,may,must +動詞原形否定句:主語+can,may,must +not +動詞原形疑問句:Can,May,Must +主語+動詞原形1. can,may,must的肯定句You may eat lunch,but you must wash your hands.你可以吃飯,但是你必須洗手.(1)cana.表示能力;能,會She can run fast,but I can't.她很會跑,但是我不會.b.表示可能;能夠I can get there in ten minutes.我十分鐘之后就可以到那兒.(表示一種可能性)c.表示允許;許可You can use this dictionary.你可以用這本字典.*和be able to比較can只有現在式和過去式,而be able to可以用于各種時態.can(could)表示能力時,可用be able to代替.I can(=am able to)pay for the book. 我買得起那本書.He will be able to tell you the news soon. 他很快就能告訴你消息了.She has been able to come to school. 她已經能去學校了.(2)maya.表示請求、許可May I borrow your pen?我可以借你的鋼筆用一用嗎?b.可能、或許Tomorrow I may go shopping.明天,我可能(或許)去商店買東西.He might be our new teacher.他或許是我們的新老師.(3)musta.必須、應該(表示有做某一動作的必要或義務)You must buy a ticket.你必須買一張票.b.一定、準是(表示有把握的判斷或推測,一般只用于肯定句中)在You must這一句型中,它的意思與祈使句相同.You must get up early. =Get up early.你必須早起.You must study hard. =Study hard.你必須用功讀書.He must be our new teacher.他肯定是我們的新老師.2.表示推測的用法can , could ,may ,might ,must 皆可用來表示推測,其用法如下:* ,might 表示推測時不表示時態,其推測的程度不如can ,* ,could 用于否定句和疑問句中.句型:主語+ can't , couldn't +be +動詞ing.(否定句)Can ,Could +主語 +be +動詞 ing.(疑問句)They can't be cleaning the room now.他們現在不可能在打掃房間.* ,might , must 用在肯定句中.句型:主語+ may ,might ,must +be +動詞 -ing (表示對現在發生動作的推測)He must be sleeping . 他現在肯定在睡覺.d.但如果上述這些詞 (must ,can't… ) + have +過去分詞則指對過去已發生的事進行推測.The road is wet. It must have rained last night .地是濕的;昨天晚上肯定下雨了.There isn't any water on the road . It (can't ) couldn't have rained last night .地面上一個水滴都沒有,昨天不可能下雨了.(四) have to的用法1. have(has)to +動詞原形。
3.情態動詞的句子怎么轉換成被動語態啊
那就舉幾個例子看看吧.
(其實規則就是: 在情態動詞后加上be, 再將謂語動詞(實義動詞)變成過去分詞, 其余就是平常的被動語態轉換, 即將原句中的賓語變成主語, 原句中的主語加上by之后變成狀語.)
1. Must
You must finish homework before supper.
改被動語態: Homework must be finished (by you) before supper.
2. Should
Parents should teach children no later than 3 years old.
改被動語態: Children should be taught by parents no later than 3 years old.
3. Have to
They have to hold a meeting in the park.
改被動語態: A meeting has to be held by them in the park.
4. Can
Lily can carry that bookshelf easily.
改被動語態: That bookshelf can easily be carried by Lily.
5. Need
Tom needs to train this dog everyday.
改被動語態: This dog needs to be trained by Tom everyday.
希望可以幫助到你理解吧。
4.英語中過去時的情態動詞句型公式
情態動詞+動詞完成式即“情態動詞+ have + done分詞”,表示對過去行為或動作進行推測、評論或判斷。
1. must have done
must have done 表示對過去某事的肯定猜測。其否定或疑問形式都用can(could) 來表示.
例如:
Since the road is wet, it must have rained last night.
He can't have missed the way. I drew him a map.
“The dictionary has disappeared. Who could have taken it?”
當然對現在發生或將來發生的事情,要用must do 表示猜測, 否定為can't do.
He must understand that we mean business.
You must be hungry after a long walk.
* / might have done
may / might have done 表示推測過去某事“也許”發生了.may 比 might 表示的可能性在說話人看來稍大些。
例如:
I can't find my keys. I may / might have left them at the school yesterday.
3. could have done 在肯定句型中, 往往用作委婉的批評. 本應該做什么,而沒做; 有時也用作猜測.
You could have told us earlier.
Tom could have taken the dictionary.
4. ought to / should have done和 ought not to / shouldn't have done
ought to / should have done 和 ought not to / shouldn't have done 用于對已發生的情況表示“責備”、“不滿”,
分別表示“本應該…”和“本不應該…”。例如:
1)With all the work finished, I should have gone to the party last night.
2)You ought not to have made fun of him. He is not the one you laugh at but learn from.
5. needn't have done
needn't have done 表示過去做了某事,但沒有做的必要, 意為“本沒必要…”。例如:
You needn't have waken me up; I don't have to go to work today.
注:表示推測過去某動作發生的可能性時,就表示的可能性程度而言,must最大,could其次,may更次之,
might最小。例如:
“I wonder how Tom knew about your past.”
“He must / could / may / might have heard of it from Mary.”
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