1- 肯定句 - 肯定句是指用肯定的语气来陈述的句子。如: I’m a student. She is a doctor. He works in a hospital. There are four fans in our classroom. 家长可以让孩子记住一个简单的特征,肯定句是用表示肯定的意思,即不含有否定词“不”。 2- 否定句 - 和肯定句相反,否定句表示某一否定意思,句中一定有not。如: I’m not a student. She is not (isn’t) a doctor. He does not (doesn’t) work in a hospital. There are not (aren’t) four fans in our classroom. 否定句的形式有三种可能: 1.be动词(am、is、are、was、were)+not 2.情态动词(can、must、should)+ not 3.助动词(do、does、did) + not