小学英语句型转换之肯定句变否定句.ppt

,小学英语句型转换 肯定句变否定句,一、概念：什么是肯定句和否定句？,肯定形式肯定句,否定形式否定句,陈述句,陈述句：说明一件事情、一个想法，提出一个观点或表达自己心情的句子。特点是：句末都是句号，用降调读！,肯定句变否定句的方法,1.含“be动词和情态动词”型，直接在be动词或情态动词后加not,其它照抄不变。,be动词包括：am,is,are,was,were. 常见的情态动词有：can,could,would,will,may等等。,例句：I am a student.,I am not a student.,He is a boy.,He is not/isnt a boy.,I can speak English.,I can not/cant speak English.,肯定句变否定句的方法,注意缩写： is not = isnt, are not = arent , was not = wasnt, were not = werent, am not没有缩写， 但是I am = Im can not = cant, would not = wouldnt could not = couldnt, will not = wont,肯定句变否定句的方法,2.含“实意动词”型，转换否定句时，记住五个字“一加一还原”的原则。“一加”即在实意动词前加助动词的否定dont,doesnt或didnt。“一还原”即把句中的实意动词变回原形。,注意：在一般现在时中，当主语是第一、二人称或复数时，加dont来否定；当主语是第三人称或单数时，加doesnt来否定； 在一般过去时中，一律用didnt来否定。,例句：I like apples.,I dont like apples.,He likes apples.,He doesnt like apples.,She worked last night.,She didnt work last night.,肯定句变否定句的方法,要注意的特殊情况： 遇到some 变 any; 遇到too/also变either; 遇到and 变 or; 遇到always 变 never。,例句:1.There are some boys in the classroom.,There arent any boys in the classroom.,2.The girl can sing and dance.,The girl cant sing or dance.,相关练习：,1.Mike would like some chicken. Mike_like _ chicken. 2.He often goes to bed at ten. He often _ _ to bed at ten. 3.Mary is a teacher,too. Mary _ a teacher ,_. 4.They went to Shanghai yesterday. They _ _to Shanghai yeste