动词的单复数 第三人称单数做主语时，一般在动词词尾加S。第一人称，第二人称单数和复数做主语时，动词用原型。比如： The cat makes friend with the dog. I go to school alone. 猫和狗做朋友。 我一个人去上学。 做一做：圈出括号中的正确的单词完成句子。 1. Two cats ( play, plays) on the stairs. 2. A girl (see, sees) a tree. 3. They (eat, eats)some friut. 助动词 助动词是语法功能词，自身没有意义，不可单独使用，它协助实义动词构成谓语动词。 实义动词的一般现在时的否定句和疑问句借助于助动词do或does来构成， 否定句中：当主语时第三人称单数时，就用does来帮助，后接动词原形。 He has a knife.-------He doesn’t have a knife. 当主语时第一，二人称或是第三人称复数时，就用do 来帮助。 They like apples.--------They don’t like apples. 由do或does构成的疑问句句式为： 1. 一般疑问句的句式： Do + I /We/ You/ They + 动词原形…..？ Does + he /she/ it + 动词原形….？ 回答语： Yes , I /We/ You/ They do. No, I /We/ You/ They don’t. Yes, he /she/ it does. No, he /she/ it doesn’t. 如：------Do they any eggs?---- Yes, they do. 2. 特殊疑问句的句式： 特殊疑问词（如： What/ Where/ When….）+ 一般疑问句？ Where does she live? ( 她住在哪里？) 练习题： 一．e.g My sister likes apples, but he doesn’t like pears. × ∨ 1. She_____ ______, but she ______ ______ ______. 2. He______ ______, but she _______ ______ ______. 3.Candy ______ ______,but she______ ______ _______. 4._____ Mr. Zhang______ _______? No, he ______. But he _______ ______. 5.______ your best friend ______ _______? No, he ______. But he _______ _______. 二．根据提示做出回答。 1.Do you like cats？（作肯定回答） Yes, ________________. 2.Does your mother like kangroos? (作否定回答) No, ________________. 3.I like chips.( 改I 为She) ______ ________ chips. 4.He likes rabbits and dogs. ( 改She 为I) ______ ________ rabbits and dogs. 5.Candy does her homework every day. (改为否定句) Linda ______ ______ her homework every day. 本文来源：https://www.wddqw.com/doc/0462d31e2c3f5727a5e9856a561252d380eb20f6.html