So vs. Such

such + a/an + (adjective)+ singular count noun + (that):

1. This has become such a mess that we will have to start over.
2. He is such a danger to himself that he will have to be hospitalized.
3. Why was that such a traumatic event in her life?

such + (adjective)+ singular noncount noun + (that):

4. Such information should be made available to everyone.
5. I have never seen him display such confidence.
6. Such compelling evidence cannot be ignored.

such + (adjective)+ plural count noun + (that):

7. "Such persons shall enjoy the protection of the present treaty."
8. Such matters are best discussed in private.
9. Such subtle distinctions are unnecessary in the present context.

so + adjective/adverb + (that):

10. The economic stimulus package is so crucial to economic growth that the president is personally calling members of Congress.
11. The Internet makes it so easy for students to cheat that many teachers are now using special software to catch instances of plagiarism.

12. The food at that restaurant was so thoroughly uninteresting that I will never go back.
13. Credit cards are not so readily accepted in some countries.

14. Our company is doing so well that we have almost doubled the number of our employees in less than a year.
15. I'm surprised to see his name mentioned so frequently in the papers.

16. That company has spent so much on advertising that it had to raise its prices.
17. We have saved thousands of dollars because the new system is so much more efficient than the old one.

18. There are so many houses for sale in our are that prices have come down considerably.
19. Our city has so many spectacular restaurants that it is difficult to decide where to eat.

20. So little is known about that disease that it is difficult to treat it.
21. There is so little time to do all that one would like to do.

22. So few jobs were created by the tax cut that the president is proposing a new stimulus package.
23. That is an excellent restaurant, but so few people know about it that I am afraid it will go out of business.

24. Why do politicians so often forget their campaign promises?
25. So far, the economists have been correct in their predictions. [so far = until now]
26. So long as the government spends more than it receives, the national debt will increase.[so long as = as long as = provided that]

Notes:

is used before a singular count noun [1-3].

such without a/an is used:
      before noncount nouns [3-5]
      before plural nouns [6-8]

so is used:
      before an adjective alone [10-11]
      before an adverb + adjective [12-13]
      before an adverb alone [14-15]

So is also used with much, many, little, few, often, far, long, etc. [16-26]