The intensive use of so (sense 2b) is widely condemned in college handbooks but is nonetheless standard <why is American television so shallow? — Anthony Lewis><the cephalopod eye is an example of a remarkable evolutionary parallel because it is so like the eye of a vertebrate — Sarah F. Robbins><the kind of sterile over-ingenuity which afflicts so many academic efforts — Times Literary Supplement>. There is no stigma attached to its use in negative contexts and when qualified by a dependent clause <not so long ago><was so good in mathematics that he began to consider engineering — Current Biography>. The denotation in these uses is, of course, slightly different (see sense 2a). Another emphatic use of so (sense 2e) has developed more recently and occurs mostly in informal contexts.
Examples of SO
I don't think they can score twice in so short a time.
There has always been an interest in genetic cloning, but never more so than in recent years.
He looked so handsome in his suit.
We are all so excited about the trip.
I'm so happy that you decided to join us for dinner.
I feel so much better after taking that nap.
Thank you so much for your help.
He dislikes her so much that he won't even talk to her.
The test was not so very hard after all.
“He is about so tall,” she said, raising her hand about six feet in the air.
Origin of SO
Middle English, from Old English swā; akin to Old High German sō so, Latin sic so, thus, si if, Greek hōs so, thus, Latin suus one's own — more at suicide
—used in speech to introduce a statement or question
Full Definition of SO
a: with the result that <the acoustics are good, so every note is clear>
b: in order that <be quiet so he can sleep>
archaic: provided that
a: for that reason :therefore<don't want to go, so I won't>
b (1) —used as an introductory particle <so here we are> often to belittle a point under discussion <so what?>(2) —used interjectionally to indicate awareness of a discovery <so, that's who did it> or surprised dissent