The demonstrative adjectives—this/that/these/those—tell us where an object is located and how many objects there are.
This/That
This and that are used to point to one object. This points to something nearby while that points to something “over there.”
Examples:
This dog is mine.
This is mine.
That dog is hers.
That is hers.
These/Those
These and those refer to more than one object. These points to things nearby while those points to things “over there.”
Examples:
These babies have been smiling for a while.
These are mine.
Those babies in the nursery have been crying for hours.
Those are yours.
Source: Grammarbook
