那么祈使句有什么 样的特点呢？
例如： (无主语you)Come in ,please.
特点一：祈使句无主语，说话对象是第二人称 you，因此也可理解为 省略了主语you。
特点2：以动词原形开头，无时态和 数的变化

例如: Wave to say goodbye. Put away your things.
特点3：祈使句有肯定和否定两种形式。
肯定祈使句的句型有： 1、Have a rest here ,please Do形---动词原形开头： V原+其他成分。 2、Be a good boy. Be形---动词be开头： Be+其他成分 3、Let me help you. Let形---Let sb. do sth.

否定祈使句的句型有： 1、Do形和Be形的否定： 在句首加Don’t构成。 Don’t forget me . Don’t be late for class. 2、Let 形的否定有两种： Let sb. not do sth. Let him not go. Don’t let sb. Do sth. Don’t let him go. 3、no 开头—用来表达禁止 性的祈使句。 No smoking. No fishing. No photos.
Practice: think about your school rules

What are allowed ?

What are not allowed?
Practice: think about your school rules

What are allowed ?

What are not allowed?
Listen to your teacher Don’t fight with others. carefully. Don’t be late. Be polite to your classmates. No smoking. Please take notes in class. Let him not run in the Let us help each other. room.
祈使句 imperative sentences
请观察下列句子，总 结什么是祈使句
1. 2. 3. 4.
Open the door, please. Don’t talk in class. Be careful. Stand 请求、命令、建议 或劝告等的句子叫做祈使句。