Unit 12,Dont eat in class,classroom,uniform,3a Fill in the blanks with the correct words,uniform classroom sports shoes,sports shoes,Grammar,肯定祈使句 Sit down. Come in. Eat at home,否定祈使句 Dont sit down. Dont come in. Dont eat at home,祈使句是用来表示请求、命令、叮嘱、号召或者劝告等的句子, 这类句子的主语常是第二人称you,也就是听话者,因而you常省去了。祈使句的开头是动词原形,Listen to music outside. Dont listen to music outside. Do your homework at school. Dont do your homework at school,如: Lookout!小心! Waithereforme!在这等我,Besuretocomehereontime! 务必准时来到这里! 祈使句的否定形式多以do