单元语法小专题(Grammar Focus)
语法精讲
一、祈使句
祈使句常用来表示命令、指示、请求、要求或建议等。
1．当主语是第二人称you时，you通常被省略。
这种祈使句一般以动词原形开头。
它的否定形式是在动词原形前加Don't。
如：
Be more careful next time.下次仔细点。
Come to school earlier next time.下次早点来学校。
Don't play computer games.不要玩电脑游戏。
在祈使句的句首或句尾加please，可以使祈使句的语气更委婉。
注意：在句尾加please 时，要在please前加逗号。
如：
Please speak loudly.＝Speak loudly，please.请大声讲话。
2．带有第一、第三人称主语的祈使句通常以let为引导词，一般用来提建议。
如：
Let's watch the cartoon now.现在我们看卡通片吧。
Let's/Let me祈使句的否定形式是Let's/Let me not…或Don't let's/let me …；“Let ＋第三人称”的否定形式为Don't let ＋第三人称…。
如：
Let's not play soccer in the street.我们不要在街上踢足球。
Don't let her watch so much TV.不要让她看这么多电视。
二、可数名词与不可数名词
普通名词分为可数名词和不可数名词。
1．可数名词可以用具体的数词来修饰，也可以用“数词＋计量名词＋of ＋可数名词的复数形式”来表示。
如：three apples三个苹果；two bags of watermelons两袋西瓜2．不可数名词没有复数形式，表示量时用“数词＋计量名词＋of ＋不可数名词”结构。
如：a cup of milk一杯牛奶
3．可数名词的量可以用how many提问；不可数名词的量可以用how much提问。
4．some，any，a lot of，lots of等既可以修饰可数名词，又可以修饰不可数名词。
语法精练
Ⅰ.用括号内所给单词的适当形式填空。
1．________(keep) quiet in the library.
2．Don't ________(swim) in the river，please.
3．Please don't ________(be) late for school next time.
4．You should not eat too much ________(meat)．
5．They visited two big ________(factory) last month.
6．There ________(be) some bread on the table. You can have some.
7．Would you like to buy some ________(salt), Mrs. Smith?
8．Both his uncle and his aunt are famous ________(scientist)．
9．How much ________(coffee) is there in the cup?
10．How many ________(watermelon) did you buy yesterday?
Ⅱ.按要求完成下列句子，每空一词。
11．You must listen to the teacher carefully. (改为祈使句)
________ ________ the teacher carefully，please.
12．You can't pour the water into the pot. (改为祈使句)
________ ________ the water into the pot.
13．I have two brothers. (对画线部分提问)
________ ________ brothers do you have?
14．There is a little honey in the fridge.(对画线部分提问)
________ ________ ________ is there in the fridge?
15．There is a tomato in the box.(用three代替a改写句子)
There ________ three ________ in the box.
Ⅲ.根据汉语意思完成句子，每空一词。
16．请看第二幅图。
________ ________ the second picture，please.
17．会议室里有几位工程师？
________ ________ ________ are there in the meeting room?
18．凯特，请不要打开搅拌机。
Kate，please ________ ________ ________ the blender.
19．我们一起做香蕉奶昔吧。
________ ________ banana milk shake together.
20．我想要一杯酸奶和两个汉堡包。
I would like ________ ________ ________ ________ and two ________．
单元语法小专题(Grammar Focus)
Ⅰ.1.Keep 2.swim 3.be 4.meat 5.factories 6.is7.salt8.scientists
9．coffee10.watermelons
Ⅱ.11.Listen to12.Don't pour13.How many14.How much honey
15．are；tomatoes
Ⅲ.16.Look at17.How many engineers18.don't turn on19.Let's make20.a/one cup of yogurt；hamburgers。