用所给动词的适当形式填空。1. Mr Brown will go fishing if it____(not rain) tomorrow.2. I think he(be) back in a week.3.－Who (knock) at the door?－I don't kn-九年级英语
在主语后谓语动词前加助动词don’t（I,you,以及复数), doesn’t（单数she,he,it）变成否定句，助动词后的动词要变成动词原形。
例：
①陈述句：We get up at 7:00 every morning.
疑问句→Do you get up at 7:00 every morning?
否定句→We don’t get up at 7:00 every morning.
②陈述句：She has a little brother.
疑问句→ Does she have a little brother?
否定句→ She doesn’t have a little brother.
一般现在时的表达方法：
主要通过谓语动词的变化和用时间词语来表示，其中最主要的是谓语动词的变化。现在一般时动词变化的规则是：
1.如果主语是名词复数和第一人称I、 we ，谓语动词不用做任何变化，即仍然用动词原形表示：
We usually go to school at 7:30. 我们通常7:30上学去。[go]
My parents give ten yuan to my sister every week.我父母每星期给我妹妹十元钱。[give]
2.主语是任何一个单数名词或者是第三人称单数，谓语动词要进行必要的变化。特别提一点：不可数名词也算作单数处理。
3.谓语动词的变化规律是：
第三人称单数的构成见下表：
![Ann often _____ lunch at home with her parents.[ ]A. have B. has C. eat D. eating -七年级英语](http://www.00-edu.com/d/file/ks/4/2/yibanxianzaishi/2020-01-10/small40b2a268356d07504139412744797e7b1578586290.png)
![My father likes ____ TV. He ____ TV every evening.[ ]A. watching; watch B. watching; watches C. watch;watches D. watches; watches-七年级英语](http://www.00-edu.com/d/file/ks/4/2/yibanxianzaishi/2020-01-10/smallb871825333b9f0e6d8ca6aba8501c7f81578587670.png)
![He said that light ______ much faster than sound. [ ]A. has travelled B. went C. travels D. travelled -九年级英语](http://www.00-edu.com/d/file/ks/4/2/yibanxianzaishi/2020-01-10/small07e3495a5ee28f5eb90f50677ab131651578586475.png)
![She is going to be a reporter when she ______ up .[ ]A. growsB. will grow C. is going to growD. grew-九年级英语](http://www.00-edu.com/d/file/ks/4/2/yibanxianzaishi/2020-01-10/small9e6c519462fad76a8cc7760999a95af51578588233.gif)
