怎么区分祈使句和以动词名词化为主语的句子?

以动词名词为主语的句子一般就是陈述一件事之类的.例句：
1、Smoking is prohibited here.
2、Climbing mountains is really fun.
3、Doing much exercise is good to our healthy.
4、Reading is an art.
5、Don't put your bike on the playground.
6、Please qive me a hand.
7、Milk is good for your health.
8、Please do your homework.
9、Listening to the music is good.
10、Throwing litter about is very bad.
英语祈使句用于表达命令、请求、劝告、警告、禁止等的句子叫做祈使句,祈使句最常用于表达命令,因此在学校文法中也常称为命令句.其主语是第二人称,所以通常都省略.祈使句的动词都为一般现在时,句末则使用句号来表示结束.
例句：
1、Go and wash your hads.
2、Please be quiet.
3、Watch your steps.
4、No parking.
5、No smoking.
6、Keep off the grass.
7、Look out!Danger!
8、Don't be careless.
9、Put the boxes in the samll room.
10、Be kind to out sister.
11、Be careful when crossing the street.