2020湖南专升本网整理：专升本英语语法之介词和情态动词

一、介词
1．He usually goes to school by his father’s car.
by加上名词表示一种交通方式，中间什么都不加，如by car,by bus,by plane等；
如果名词前有其他的词修饰，则应除by以外的其他介词，此处把by改为in.
2．Please wait me at the school gate.
专升本英语语法之介词和情态动词
wait为不及物动词，需加介词for后才能再跟名词或代词做宾语。
3．He has been married with Betty for more than twenty years.
marry不跟with连用，应把with改为to。
4．I finished the work on time under the help of him.
“在…的帮助下”用with而不用under。
二.情态动词
1．He can be at home now because the light in his room is still on.
表特别有把握的肯定判断时用must，表特别有把握的否定判断时用can,can表判断时只用在否定句中。因此把can改为must。
专升本英语语法
2．He need come here before the meeting begins.
作情态动词时need用在否定，疑问和条件句中，不能用于肯定句中，而作实意动词时则可以。所以应改为：He needs to come here before the meeting begins.
3．He used to get up very early in the morning,and now he is still doing so.
used to用来表示过去常常做某事而现在不了，所以应把后半句改为：but now he is not doing so.
4．I needn’t come yesterday because all the work had been finished.
由于情态动词本身不体现时态，所以在谈论过去的事情时在情态动词后加have done，因此在needn’t后加have。
5．You hadn’t better stay up too late because you have to get up early tomorrow.
had better的否定在better后面加not.