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2020大學英語六級語法知識備考匯總【二】
英語六級語法知識：特殊的虛擬語氣詞should
1) It is demanded / necessary / a pity + that…結(jié)構(gòu)中的主語從句的謂語動詞要用should 加動詞原形， should 可省略。
句型：
(1)suggested
It is (2)important that…+ (should) do
(3) a pity
(1)suggested, ordered, proposed, required, demanded, requested, insisted; + (should) do
(2)important, necessary, natural, strange
a pity, a shame, no wonder
(3)It is suggested that we (should) hold a meeting next week.
It is necessary that he (should) come to our meeting tomorrow.
2)在賓語從句中的應(yīng)用
在表示命令、建議、要求等一類動詞后面的從句中。
order, suggest, propose, require, demand, request, insist, command, insist + (should) do
I suggest that we (should) hold a meeting next week.
He insisted that he (should ) be sent there.
注意： 如suggest, insist不表示"建議" 或"堅持要某人做某事時"，即它們用于其本意"暗示、表明"、"堅持認為"時，賓語從句用陳述語氣。
The guard at gate insisted that everybody obey the rules.
判斷改錯:
(錯) You pale face suggests that you (should) be ill.
(對) Your pale face suggests that you are ill.
(錯) I insisted that you ( should) be wrong.
(對) I insisted that you were wrong.
3)在表語從句，同位語從句中的應(yīng)用
在suggestion, proposal, idea, plan, order, advice等名詞后面的表語從句、同位語從句中要用虛擬語氣，即(should)+動詞原形。
My idea is that we (should) get more people to attend the conference.
I make a proposal that we (should) hold a meeting next week.
2020大學英語六級語法知識備考【二】
英語六級語法知識：wish的用法
1)用于wish后面的從句，表示與事實相反的情況，或表示將來不太可能實現(xiàn)的愿望。其賓語從句的動詞形式為：
真實狀況 wish后
從句動作先于主句動詞動作 現(xiàn)在時 過去時
(be的過去式為 were)
從句動作與主句動作同時發(fā)生 過去時 過去完成時
(had + 過去分詞)
將來不大可能實現(xiàn)的愿望 將來時 would/could +
動詞原形
I wish I were as tall as you. 我希望和你一樣高。
He wished he hadn't said that. 他希望他沒講那樣的話。
I wish it would rain tomorrow. 我希望明天下雨就好了。
2)Wish to do表達法。
Wish sb / sth to do
I wish to see the manager. = I want to see the manager.
I wish the manager to be informed at once. (= I want the manager to be informed at once.)
2020大學英語六級語法知識備考【三】
英語六級語法知識：比較if only與only if
only if表示"只有";if only則表示"如果……就好了"。If only也可用于陳述語氣。
I wake up only if the alarm clock rings. 只有鬧鐘響了，我才會醒。
If only the alarm clock had rung. 當時鬧鐘響了，就好了。
If only he comes early. 但愿他早點回來。
2020大學英語六級語法知識備考【四】
英語六級語法知識：It is (high) time that
It is (high) time that 后面的從句謂語動詞要用過去式或用should加動詞原形，但should不可省略。
It is time that the children went to bed.
It is high time that the children should go to bed.
2020大學英語六級語法知識備考【五】
英語六級語法知識：need "不必做"和"本不該做"
didn't need to do表示： 過去不必做某事, 事實上也沒做。.
needn't have done表示： 過去不必做某事, 但事實上做了。
John went to the station with the car to meet Mary, so she didn't need to walk back home. 約翰開車去車站接瑪麗，所以她不必步行回家了。
John went to the station with the car to meet Mary, so she needn't have walked back home. 約翰開車去車站接瑪麗，所以她本不必步行回家了。 (Mary步行回家，沒有遇上John的車。)
典型例題
There was plenty of time. She ___.
A. mustn't have hurried B. couldn't have hurried C. must not hurry D. needn't have hurried
答案D。needn't have done. 意為"本不必"，即已經(jīng)做了某事，而時實際上不必要。
Mustn't have done 用法不正確，對過去發(fā)生的事情進行否定性推斷應(yīng)為couldn't have done, "不可能已經(jīng)"。 must not do 不可以(用于一般現(xiàn)在時)。