1、句子变否定句的规则：1. 句子有 be 动词的，直接在 be 动词后面加 not，其他句子成分不变。例：I am a student. (not) I am not a student.He is a doctor. (not) He is not a doctor.2. 句子里有情态动词 can 和助动词 will 时，直接在 can 和 will 后面加 not，其他句子成分不变。例：I can swim. (not) I can not swim.You will go to school at 7:30. You will not go to school at 7:30.3. 句子里
2、没有 be 动词、情态动词 can 和助动词 will 时，借助于助动词 do 和 does，在动词前加 dont/doesnt，第三人称单数时用doesnt 且后面的动词改为原形，其他用 dont。例：I like apples.(not) I dont like apples.She likes bananas. (not) She doesnt like banana.They have a box. (not) They dont have a box.练习一写出下列单词的第三人称单数。三单：cook eat read borrow buy write wash watch go do
3、 study fly cry have 第一人称有（I, we ） ，第二人称有（you, you ） ，其他人称都是第三人称。第三人称的单数，动词有以上的五种变化。做题时，先判断是第几人称。第三人称单数才有以上的五种变化。二补充完整。1. What do you do on Monday?I (去上学) on Monday.2What Tony do on Saturday?He (去上学) on Saturday.3. What subjects do you like? I music.4. What subjects Jenny like? She science.5. they wa
4、nt a skateboard? No, they .6. she want a computer ? No, she .一写出下列单词的第三人称单数。cook cooks eat eats read reads borrow borrows buy buys write writes wash washes watch watches go goes do does study studies fly flies cry cries have has 二补充完整。1. What do you do on Monday? I 是第一人称，加动词原形I go to school (去上学) on Monday.2What does Tony do on Saturday? Tony 三单He goes to school (去上学) on Saturday.3. What subjects do you like? I like music.4. What subjects does Jenny like? She likes science.Jenny 三单5. Do they want a skateboard? No, they dont .第三人称，但是是复数6. Does she want a computer ? No, she doesnt .She 三单
