So and such can be used as emphasizers, that is, words that help us put the stress on something.
So is used with adjectives or adverbs, while such is used with nouns (with or without adjectives).
This car goes so fast! (adverb)
He's so intelligent! (adjective)
He's such an intelligent man! (noun)
Image: 'the writing on the wall' by ugod
Notice that when such is followed by a countable singular noun, we must use a or an before it. If the noun is plural no article should be used.
Italy is such a beautiful country! (singular countable noun)
It's such an important book!
They are such interesting people! (people is plural, so there is no article before it)
Such can be used before a noun with no adjective if the noun has a gradable meaning that can be emphasised, like fun, mess, fool...
They are such fun to be with!
Your room is such a mess!
Expressions with so and such can be followed by that-clauses that show result or consequence.
It was so hot that we had to stop for a cold drink.
It was such a beautiful day that we decided to go out for a walk.
So can be used with much and many:
So much + uncountable nouns
You put so much salt in the soup that I cannot eat it.
So many + countable plural nouns
There are so many students in my class that it's difficult to hear the teacher.
Try these two exercises: