This, That, These, Those are called demonstratives and they are used to show the relative distance between the speaker and the noun. Demonstrative PronounsWe use this (singular) and these (plural) to refer to something that is here / near. Examples:
This is my car. (singular)
These are our children. (plural)
We use that (singular) and those (plural) to refer to something that is there / far. Examples:
That is our house. (singular)
Those are my shoes. (plural)
Note that the verb changes (i.e. singular / plural) depending on the pronoun that you use. You can also use Demonstrative Pronouns by themselves:
Did you do that?
I'd like to buy these?
Which of those would you like?
Demonstrative AdjectivesYou can also use demonstratives before a noun. These are called demonstrative adjectives. The Demonstrative Adjective needs to agree (= be the same form) as the noun. Examples of demonstrative adjectives: