漫话英语中的肯定句变否定句
英语中的肯定句变否定句是一种常见的练习和考试题型。在把肯定句变为否定句时,通常在助动词、情态动词或连系动词be的后面加上not 即可。如: 1.We are teachers. → We aren’t teachers. 2.He works on a farm. → He doesn’t work on a farm. 3.He has come. → He hasn’t come. 但有些情况下,按上述例句去变未必对,应注意以下几种特殊情况: 一、当everyone,everybody,someone,some-body,everything,something等不定代词作肯定句的主语时,肯定句变否定句一般不加not,而要把everyone和someone变为no one,把everybody和somebody变为nobody,把everything和some-thing变为nothing构成否定句。如: 1.Something is wrong with my bike. → Nothing is wrong with my bike. 2.Everyone is here. → No one is here. 二、含有always的肯定句变为否定句时,只将always变为never即可。如: He always goes to school by bike. → He never goes to school by bike. 三、含有often的肯定句变为否定句时,只将often变为seldom即可。如: They often play football after school. → They seldom play football after school. 四、含有nearly的肯定句变为否定句时,只将nearly变为hardly即可。如: He could nearly believe that was true. →He could hardly believe that was true. 五、含有a few,a little的肯定句变为否定句时,只将a few变为few,将a little变为little即可。如: 1.I have a few friends in Tianjin. → I have few friends in Tianjin. 2.There is a little water in the glass. → There is little water in the glass. 六、当all,both作肯定句的主语或主语的修饰语时,可将all变为none,将both变为neither构成全部否定,也可将句子的谓语部分变成否定形式,构成部分否定,但采用这两种形式把句子变成否定时,其句意有所不同。试比较: 1.All of them came here yesterday. → None of them came here yesterday. 他们昨天没有一个人来这儿。 → All of them didn’t came here yesterday. 他们并非都是昨天来这儿的。 2.Both pens are mine. → Neither pen is mine. 两枝钢笔都不是我的。 → Both pens aren’t mine. 两枝钢笔并不都是我的。 七、若think,believe,suppose,except等表示猜测的动词引导宾语从句,变为否定句时,要否定主句的谓语动词,而不否定宾语从句,但译成汉语时要否定从句(此称之为“否定转移”)如: I think she is right. → I don’t think she is right. 我认为她不对。 八、have(has)在肯定句中作实义动词时,肯定句变否定句有两种情况: (一)have(has)表示所有关系,肯定句变否定句时可在其后直接加not,也可在其前面加“助动词+ not”。如: I have a cat. → I haven’t/don’t have a cat. (二)have(has)表示动作,肯定句变否定句时只能在其前面加“助动词+ not”。如: He has lunch at school every day. → He doesn’t have lunch at school every day. 九、含有had better的肯定句变为否定句时,通常在had better后加not。但值得一提的是,将肯定句变为否定的一般疑问句时,可在had better后加not,也可在had后加not,但这两种否定结构在意义上有所不同。如: We had better go now. → We had better not go now. 我们最好现在别去。 → Had we better not go now? 我们现在不去不是更好吗?(我们不去,好不好?) → Hadn’t we better go now? 我们现在去不是更好吗?(我们还是去好,你不同意吗?) 十、祈使句的否定形式是在句首加don’t,但以let开头的祈使句变为否定句时,可在不定式前加not(最常见),也可在let前加don’t(不多见),还可在let后加don’t(很少见)。如: 1.Listen to me. → Don’t listen to me. 2.Let me go. → Let me not go.(常用) → Don’t let me go.(英国英语非正式用法) → Let me don’t go. (美国英语非正式用法) 十一、含有also,too的肯定句变为否定句时,需将also,too换成相对应的词either,且放于句末。如: He is also a worker. / He is a worker, too. → He isn’t a worker, either. 十二、含有用and连接的并列成分的肯定句变为否定句时,应将and变为or,表示前后成分均被否定。and前后为名词时,也可用“no... and no...”表示否定。但如果and连接的两项内容是一个整体则不用此种形式。如: 1.He can speak English and Chinese. → He can’t speak English or Chinese. 2.It has feet and legs. → It has no feet and no legs. 3.He is a teacher and a writer. 他是位教师兼作家。 → He isn’t a teacher and a writer. 他不是教师兼作家。(他不是教师,但是作家。)