It was so hot outside that all the plants died. He was so good, they hired him on the spot.
2
To the (implied) extent.
I need a piece of cloth so long. [= this long]
3
In a particular manner.
Place the napkin on the table just so. If that's what you mean, then say so; (or do so).
4
In the same manner or to the same extent as aforementioned; also.
Just as you have the right to your free speech, so I have the right to mine. Many people say she's the world's greatest athlete, but I don't think so. "I can count backwards from one hundred." "So can I."