this

this is on the Basic English 850 List.

thing - this - though

this is one of the 1000 most common headwords.

thirty - this - though

Determiner

Determiner
this

A person points to this chair.

(definite) (singular) (count & non-count) You use this to show which thing or idea you are talking about. You use it when the thing or idea is close to you.
This trip was a great idea.

Which book is yours, this one or that one?
(definite) (singular) (count & non-count) The thing indicated without mentioning the noun.
This is my hand.
(indefinite) (singular) (count & non-count) You use this in stories, jokes etc to introduce a person or thing into the story.
So this guy walks up to me and asked if I have any fish.