问几个句子的介词用法

题目

问几个句子的介词用法
1、I'll need it tomorrow morning.
2、Shall we start sometime later this week,say,Friday?
3、The boy was running home after school when he fell and skinned his knee.
为什么在第1句的tomorrow,第2句的friday,第3句的home前面都不用加介词?

答案

时间状语（this afternoon,tomorrow,next morning）可以省略介词.
home这里是做副词 副词本身就不加介词.
at home 中home 是名词“家”