so

(adjective): True, accurate.
(adjective): In that state or manner; with that attribute. A proadjective that replaces the aforementioned adjective phrase.
(adjective): Homosexual.
(adverb): To the (explicitly stated) extent that.
(adverb): To the (implied) extent.
(adverb): In a particular manner.
(adverb): In the same manner or to the same extent as aforementioned; also.
(adverb): With as To such an extent or degree; as.
(conjunction): In order that.
(conjunction): With the result that; for that reason; therefore.
(conjunction): Provided that; on condition that, as long as.
(interjection): Used after a pause for thought to introduce a new topic, question or story.
(interjection): Short for so what.
(interjection): Used to connect previous conversation or events to the following question.
(interjection): Used to introduce a rhetorical question.
(interjection): Be as you are; stand still; used especially to cows; also used by sailors.

That is so. You are responsible for this, is that not so?
Is he so?
It was so hot outside that all the plants died. He was so good, they hired him on the spot.
I need a piece of cloth so long. [= this long]
Place the napkin on the table just so. If that's what you mean, then say so; (or do so).