This:
–pronoun
1.(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.
2.(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.
3.(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.
4.what is about to follow: Now hear this! Watch this! –adjective
5.(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.
6.(used to indicate the nearer in time, place, or thought of two persons, things, etc.; opposed to that).
7.(used to imply mere contradistinction; opposed to that).
8.(used in place of an indefinite article for emphasis): I was walking down the street when I heard this explosion. –adverb
9.(used with adjectives and adverbs of quantity or extent) to the extent or degree indicated: this far; this softly. —Idiom
10.with this, following this; hereupon: With this, he threw down his glass and left the table.