1 used for talking about sb/sth that is close to you in time or space （用于指时间或空间上较近的人或事物）这，这个: Have a look at this photo. 看看这张照片。These boots are really comfortable. My old ones weren't. 这双靴子真的很舒服，我的旧靴子可不舒服。Is this the book you asked for? 这是你要的书吗？These are the letters to be filed, not those over there. 这些才是要归档的信件，不是那边那些。This chair's softer than that one, so I'll sit here. 这张椅子比那张软，所以我要坐在这里。

2 used for talking about sth that was mentioned or talked about earlier （用于指先前提过或说过的事物）: Where did you hear about this? 你从哪里听到此事？

3 used for introducing sb or showing sb sth （介绍某人或向某人展示某物时用）: This is my wife, Claudia, and these are our children, David and Vicky. 这是我妻子克劳迪娅，这是我的孩子戴维和维基。It's easier if you do it like this. 你这么做就会容易一些。

4 (used with days of the week or periods of time) of today or the present week, year, etc 当前的（某天、星期、年等）: Are you busy this afternoon? 今天下午你忙吗？this Friday (= the Friday of this week) 本星期五

5 (informal 非正式) (used when you are telling a story) a certain （讲故事时用）某一个: Then this woman said... 接着这个女人说… this adv The road is not usually this busy. 这条路平常没有这么多车。