英语（四年级下）主要知识点整理
（例句都是课本中原句）
1.祈使句：表示请求、命令、建议等的句子。祈使句不需要主语，谓语动词用原形，句子末尾一般用感叹号。
eg: (1) Don’t walk on the grass! （否定祈使句）
(2)Let’s make a newspaper! （肯定祈使句）
2.一般现在时：经常发生的动作或状态(常与always, usually, often, sometimes, seldom, never, every day/week/year, on Sundays ...连用)
(1) be动词的一般现在时：（比较简单）
I am, We/You/They are, He/She/It is，There is+单数名词或不可数名词, There are + 复数名词
eg: It’s not beautiful, but it’s helpful.
(2) 行为动词的一般现在时：（单数第三人称的变化是重点、易错点; 助动词用do, don’t, does, doesn’t）
eg: (1)This machine cuts the potatoes.
(2) Does he live in New York?
(3) Fish live in the river and birds live in the tree. (***注意fish单数和
复数写法一样，这里fish前面没有a, 所以是复数形式，后面接谓语动词要用原形。另外，Sheep和deer单复数也是一样的形式)
3.一般过去时：表示过去发生的动作或状态（常与...ago, yesterday, the day before yesterday, last week/year/month, once upon a time, one day, the next day, in 2016...连用）
(1)be动词的一般过去时：
I/He/She/It was, We/You/They were, There was+单数名词或不可数名词, There were + 复数名词
eg：Once upon a time, there was a boy. (讲故事常用说法)
(2)行为动词的一般过去时：(助动词用did, didn’t)
①一般动词变化：
构成法：1. 动词原形+ed. 如：look--looked
2.以e结尾的词+d. 如：live--lived
3.以辅音字母+y结尾的词，改y为i, 再加ed.
如：study--studied, cry--cried.
4.以重读闭音节或r音节结尾，末尾只有一个辅音字母的词，
双写这个辅音字母，再加ed. 如: clap--clapped, stop--stopped,
prefer--preferred
②不规则动词变化：如had, said, put, saw, got, ran, learnt(英式写法),
bought, came, took, went等
eg1: The animals had a concert last week.
eg2: The next day, the boy ran to the village again.
eg3: What did he play yesterday?
eg4: When did you get up last Sunday? I got up at 8 o’clock.
4.一般将来时：表示还没有发生但将要发生的事情或动作(常与tomorrow, the day after tomorrow, next year/month/week, soon, in the future, in ... minutes/hours/days...连用)
(1)Be going to+ 动词原形：多表示即将发生，最近打算、计划、安排好要做的事情，主观性较强(区分人称，be动词变化am, is, are) eg: She’s going to visit Australia.
(2)Will+动词原形：多表示即将发生的动作或状态，不受主观因素影响的单纯的将来，客观性较强(不区分人称，都用will)
(***目前小学阶段对这两种形式区分并不明显，可以互换使用) eg: We will go to the zoo on Sunday.
5.现在进行时：表示正在进行或发生的动作(常与now, at present, at this moment连用)
Be动词+动词的现在分词(***区分人称，注意动词的现在分词构成的特殊情况）
动词的现在分词构成法：
(1)一般规则：动词+ing, 如: work--working.
(2) 以e结尾的动词去掉e加ing. 如: live--living, have--having.
(3) 以重读闭音节或r音节结尾，末尾只有一个辅音字母的词，双写这个辅音字母，再加ing. 如: swim--swimming, clap--clapping, refer--referring.
(4) 以ie结尾的重读开音节的词，改ie为y, 再加ing. 如: die--dying. eg: (1) What’s happening now?
(2) Daming is making a card for his father.
(3)We are having a party.
6.购物相关话题：
（1）I want to buy a pen.
（2）It’s expensive/cheap.
（3）It costs one hundred and eighteen yuan.
（4）Who wants to buy it?
7.音乐演奏相关话题：(***演奏乐器前要加定冠词the )
(1)I played the piano yesterday.
(2)You’re playing the violin for your father.
