陈述句变为否定句

陈述句变为否定句1.如果陈述句中有be动词（am,are,is,was,were）,就在be动词后面直接加not。Iamastudent.→Iamnotastudent.Youaresad.→Youarenotsad.Sheisagoodgirl.→Sheisnotagoodgirl.Heisagoodboy.→Heisnotagoodboy.YesterdaywasMonday.→YesterdaywasnotMonday.Thestudentswerebusyyesterday.→Thestudentswerenotbusyyesterday.2.如果陈述句中有情态动词（canmustshouldmaywill等），就在情态动词后面直接加not。Icanswim.→Icannotswim.Youwillgotothepark.→Youwillnotgotothepark.3.如果陈述句中没有be动词也没有情态动词（就是实意动词），就需要借助助动词（do,does,did）来帮助否定。①当句中的动词是原形时，加don’tIlikeEnglish.→IdonotlikeEnglish.Youhavedinner.→Youdonothavedinner.②当句中的动词是第三人称单数时，加doesn’t，再加动词原形Shelikessinging.→Shedoesn’tlikesinging.Shedoesherhomework.→Shedoesnotdoherhomework.(特例)③当句中的动词是过去式时，用didn’t，加动词原形Wehadagreattimeduringourholidays.→Wedidnothaveagreattimeduringourholidays.Iwenttoschoolyesterday.→Ididnotgotoschoolyesterday.4、陈述句中的some在否定句中应改为any如：Therearesomestudentsintheclassroom.Therearenotanystudentsintheclassroom.