你好，见以下，很简单。
一.肯定句变成否定句
如果句中有be动词is，am，are 或情态动词must，can等，在其后面直接加not，
she is your mother. she isn't your mother
2.如果没有be动词或情态动词，加don't，does't或did't
she likes playing football. she doesn't like playing football.
二.肯定句变成疑问句
变成一般疑问句
如果有be或情态动词动词就把他们提前，
she is your mother. Is she your mother?
2. 如果没有就在前面加do的某种形式，第三人称用does，过去时用did
she likes playing football. Does she like playing football?
变成特殊疑问句，
要具体分析，看是对什么进行提问，简单来说，
1. 对人提问用who， she is your sister。 Who is your sister？
2.对事物用what， The book is on the desk. what it is on the desk?
3对时间用when， She will come back tomorrow. When she will come back?
4.对频率用how often等等 I play football everyday. How often does you play footall?
基本就这些了，希望能帮到你~
一、变否定时，1、有be动词后直接加not
如：He is smart.变成He is not smart.=He isn't smart.(缩写)
2、无be动词，借助先写do(一二人称)或does(三人称)后加not
如；I like English.变成I don't like English.
She like Math，变成She doesn't like math。
二、变疑问时，1、有be直接放最前，剩下的抄下来。
如 I am ready.变成Are you ready？
2、无be。同变否定 先借助do(一二人称)或does(三人称)，剩下的抄下来。
注，前有助动词，后面的动词必须写原型。
如 She teaches them math.变成Does she teach math?
希望能帮到你，(*^__^*)
什么是助词呢？能举几个例子吗？比如？
追答比如说：do，does，did。do用于第一人称和第二人称。does用于第三人称。did用于过去时。
还有have，has，had，用于完成时态。还用介绍完成时态么？