that day 可作主语、宾语、时间状语 on that day 只能作时间状语 再问: 那二者的区别? 再答: that day只能后置,on that day前置后置都可以 这个真不好说清楚,最好有例子 再问: 比如说I went to the museum that day =I went to the museum on that day =On that day,I went to the museum ,是吗 另外,再问一下, that,this开头的时间状语,何时需要用介词,何时不用? (如at that time,that morning) 再答: 你问的这些属于一类的,具体说不清,要看题目,建议你可以做做这类的专项练习,熟悉题型