若祈使句有主语，否定词don't或never要置于主语之前。

　　Don't be late tomorrow.

　　明天不要迟到。

　　Never put off what you should do till tomorrow.

　　今日事今日毕。

　　Don't you believe it.

　　决不要相信它。

　　3．let祈使句

　　Let me try.

　　让我试试吧。

　　Let Robert take charge of the marketing department.

　　让罗伯特负责市场部。

　　Let him try and he will expose his inability to work on his own.

　　让他试试，他就会明白一个人无法工作。

　　4．No＋名词/动名词

　　No smoking!

　　禁止吸烟！

　　No photos in the room.

　　该房间不许拍照！

　　[名师点津]　(1)let的否定句有两种形式。如果宾语是第三人称用"Don't let ..."；如果宾语是第一人称，则用"Let ...not ..."。如：

　　Let's not waste time.

　　咱们别浪费时间了。

　　Don't let him go.

　　别让他走。

　　(2)祈使句的主语通常为you，一般不出现。但若要强调主语，或表示急躁、厌烦、不高兴、愤怒等感情色彩，或表示向某人请求或发出命令，祈使句中可带主语。

　　You mind your own business!

　　你不要多管闲事！

　　John, you open the door.

　　约翰，你来开门。

　　(3)对祈使句的肯定形式表示强调时，在句首加do。

　　Do come earlier tomorrow.

　　明天务必早点来。

　　集中演练1

　　1－1.用祈使句改写下面的句子

　　①You'd better not come late again.

　　Don't come late again.

　　②You must be careful in the coming examination.

　　Be careful in the coming examination.

　　③Why don't you choose to work on foot at rush hours?

　　Why not choose to work on foot at rush hours?

　　④Would you like to wait a moment?

　　Please wait a moment.

　　⑤Will you please not play with my pencil?

　　Don't play with my pencil, please.

　　1－2.翻译句子

　　⑥如果你困了就上床睡吧。

　　If you feel sleepy, go to bed.

　　⑦非请莫入。

　　Do not come in unless asked.

⑧你带她去花园。