(used to indicate a person, thing, idea, state, event, time, remark, etc., as present, near, just mentioned or pointed out, supposed to be understood, or by way of emphasis)

This is my coat.

(used to indicate one of two or more persons, things, etc., referring to the one nearer in place, time, or thought; opposed to that )

This is Liza and that is Amy.

(used to indicate one of two or more persons, things, etc., implying a contrast or contradistinction; opposed to that )

I'd take that instead of this.

what is about to follow

Now hear this! Watch this!

(used to indicate a person, place, thing, or degree as present, near, just indicated or mentioned, or as well-known or characteristic)

These people are my friends. This problem has worried me for a long time.

(used to indicate the nearer in time, place, or thought of two persons, things, etc.; opposed to that ).

(used to imply mere contradistinction; opposed to that ).

(used in place of an indefinite article for emphasis)

I was walking down the street when I heard this explosion.

(used with adjectives and adverbs of quantity or extent) to the extent or degree indicated

this far; this softly.

with this

following this; hereupon

With this, he threw down his glass and left the table.