Grammar: Demonstratives: This, That, These, Those
This (for singular) and these (for plural) are used if we wish to point out a person or thing which is close.
This is my friend Peter.
These are our friends John and Peter.
That (for singular) and those (for plural) are used if we wish to point out a person or thing which is further in the distance.
That girl standing on the other side of the road is Linda.
I like those toys which are on the shelf.
– articles cannot be used if a noun is preceded by demonstratives