1.187 USAGE NOTE

You can indicate that you are referring to the same person or thing you have just mentioned by using 'this', 'that', 'these', or 'those' in front of a noun. For example, if you have just mentioned a girl, you can refer to her as 'this girl' or 'that girl' the second time you mention her. Normally, you use a pronoun to refer to someone or something you have just mentioned, but sometimes you cannot do this because it might not be clear who or what the pronoun refers to.

The use of demonstratives to refer again to something which has already been mentioned is fully explained in paragraphs 9.7 to 9.10.

1.188

In informal English, you can also use 'that' and 'those' in front of a noun to refer to people or things that are already known to the person you are speaking or writing to.

1.189

You can use 'that' in front of a noun when you are referring to something that has just happened or to something that you have just been involved with.

'That' is often used as a pronoun to refer to something that has just happened. This use is explained in paragraphs 1.123 to 1.126.