考点一　陈述句之肯定句变否定句

　　陈述句是用来叙述一件事情或表明说话人的看法、态度等的句子。包括肯定陈述句和否定陈述句。通常肯定句变否定句的方法是：

　　1. 若句中有连系动词be、情态动词或助动词，则分别在它们的后面加上not。如：

　　His mother has already called the police for help.

　　→His mother hasn’t called the police for help yet.

　　例　Sometimes you’re supposed to come early. (变为否定句)

　　Sometimes you　　　　 　　　　 supposed to come early.

　　解析：因为句中有连系动词are，所以在变否定句时，应在are后加not。　　答案：are not

　　2. 原句中没有连系动词be、助动词或情态动词时，要在行为动词前加助动词(do，does，did)与否定副词not。并注意这时的行为动词要用原形。另外，还需要将原句中的some改为any，too改为either，already改为yet。如：

　　The old man hurt his leg last Wednesday. →The old man didn’t hurt his leg last Wednesday.

　　例　He did some work this morning. (变为否定句)

　　He　　　　 do 　　　　 work this morning.

　　解析：句子的谓语动词为did，变否定句时加助动词did与not，注意这时的行为动词要用原形，句中的some变为any。　　答案：didn’t，any

　　3. 英语中有些肯定句与not连用只表示部分否定，所以在变为否定句时，只需将其中的某一(些)词语变为否定词即可。常见的这类词有both→neither，all→none，both... and... →neither... nor... ，everyone/each→no one/nobody，each/either→neither，a few→few，a little→little。如：

　　All the students are listening carefully. →None of the students is/are listening carefully.

　　Both Joy and Sam like singing Beijing Opera. →Neither Joy nor Sam likes singing Beijing Opera.

　　例　I know 　　　　 about the news. You can ask Peter. He can tell you the news.

　　A. everything         B. nothing                     　　C. anything

　　解析：从句子You can ask Peter. He can tell you the news. 可判断，“我”对这个消息一无所知，所以用否定词nothing。　　答案：B

　　4. 在含有宾语从句的主从复合句中，当主句的主语是第一人称，谓语动词是think时，如果要否定后面的宾语从句，习惯上否定主句的谓语动词。如:

　　I think she will come here soon.

　　→I don’t think she will come here soon.