在做練習(xí)時(shí)，有些題目會(huì)要求我們將肯定句變?yōu)榉穸ň洌@類題型要求同學(xué)們能夠熟練掌握兩種句型之間的轉(zhuǎn)換。并不是所有的否定句都能由肯定句加上否定詞構(gòu)成，在進(jìn)行轉(zhuǎn)換時(shí)也有一些細(xì)節(jié)問(wèn)題值得注意，下面跟隨小編一起來(lái)看一下吧。

首先我們要將陳述句按其所包含的謂語(yǔ)部分分成三類：謂語(yǔ)是be動(dòng)詞的肯定句、謂語(yǔ)是實(shí)義動(dòng)詞的肯定句與謂語(yǔ)是情態(tài)動(dòng)詞的肯定句。

謂語(yǔ)是be動(dòng)詞的肯定句轉(zhuǎn)換為否定句

直接在be動(dòng)詞后加not。如：is not，are not，am not，was not，were not。

He is a math teacher. →?He is not?a math teacher.

They were players of the school team. →?They were not?players of the school team.

謂語(yǔ)是實(shí)義動(dòng)詞的肯定句轉(zhuǎn)換為否定句

在動(dòng)詞前加助動(dòng)詞否定形式don’t/doesn’t/didn’t，動(dòng)詞的第三人稱單數(shù)形式或過(guò)去式都轉(zhuǎn)變?yōu)閯?dòng)詞原形。

He wants to go out. →?He doesn’t?want to go out.

We had a picnic in the park yesterday. →?We didn’t?have a picnic in the park yesterday.

謂語(yǔ)是情態(tài)動(dòng)詞的肯定句轉(zhuǎn)換為否定句

直接在情態(tài)動(dòng)詞后加not。

He can remember the content in detail. →?He can not remember the content in detail.

There will be a new building next year. →??There will not be a new building next year.???(will not可以縮寫為won’t)

大多數(shù)情況下，肯定句轉(zhuǎn)換為否定句只要直接加一個(gè)not就可以，但這種情況并不絕對(duì)。還有一些需要注意的點(diǎn)，肯定句中的some在否定句中要換成any，在be動(dòng)詞和多數(shù)情態(tài)動(dòng)詞之后的not可以縮寫成n’t，不過(guò)也有例外，如won’t。