it is:代表它是.比如我指着一本书说:It is a book. that is:代表那是.比如问:What's that?就答:That is a book. 这里的that就是特指问句中的. 其实it is 和that is没有什么本质上的区别 平时对话或考试中一般不会那么详细. 而there is就大大不同.它的意思是:有... 比如:There is a book on the desk.有一本书在书桌上. 还例如:There will be a meeting next Monday.下周一将有一个会议. 切记:there的后面只能跟be动词,即there is/there are/there is going/there will be