So vs Such

 The following rules explain the difference between So and Such in English.

So … that, Such … that

We use so ... that, such ... that:

a) to show a fact (usually with a result or consequence)

• Pamela Ander's feet are big.
  (Expresses a fact).
• Pamela Ander's feet are so big that she can't find shoes her size.
  (Emphasizes that you feel strongly about the size of her feet).

b) to show extreme feelings or an opinion about something

• George Bushoff is an idiot.
  (Merely a statement of fact/opinion).
• George Bushoff is such an idiot that he doesn't even know the capital of his own country.
  (Emphasizes the speaker's opinion of the intensity of George Bushoff's idiocy).

SO with adjectives and adverbs

so + adjective/adverb + that + result

• The teacher speaks so clearly that everyone can understand her.
• The sun was so strong that they got burned within 15 minutes.

SUCH + Nouns

such + a + (adjective) + singular noun + that + result
(It is common to put an adjective before the noun)

• He is such a tight person that he even reuses his servillettes.
• Christopher is such a handsome man that all the ladies want him.
• She had such a long speech that everyone stopped paying attention to her.

such + plural/uncountable noun + that + result

• She has such big feet that she has to buy special shoes.
• Woodward Restaurant has such good food that it's always full of people.

SO / SUCH in exclamations

In exclamations we drop the word 'that' and use:

i) such + noun (singular/plural)
ii) so + adjective

• You are such an idiot! (noun)
• Celebrities have such weird tastes! (noun)
• You are so stupid! (adjective)
• It's so sunny outside! (adjective)

Such-and-such

This is used to talk about a particular type of person or thing that doesn't need to be specified. It is an unstated generic placeholder.

• People from such-and-such areas tend to be wealthy.
• If you do such-and-such a job, you will become famous.