这四个单词都是指示代词
单数形式：this（这个）,that（那个）
复数形式：these（这些）,those（那些）
this（these）和that（those）的区别
通常this（these）指离说话人较近的物品,that（those）指离说话人较远的物品．指示代词既可以单独使用,也可以与名词连用．例如：
Xiaofeng,this is Xiaoyun,my friend.
These people are my friends.
That is Tom near the door.
Those people in the car are his brothers and sisters.