So and such are used to emphasize adjectives and nouns. So is used before an adjective alone, or with an adverb, while such is used when an adjective is paired with a noun. Both so and such require 'a/an' after them when used before a singular countable noun. So can also be used before a noun when modifiers like 'many' or 'much' are included, while such cannot be used in this way. Such can emphasize a noun on its own or be used with 'a lot of/lots of'. So and such can also be used in 'that' clauses to show the result of the first clause.

1. SO AND SUCH
So and such are used to strongly emphasisewords. They are stronger than
very and really. However, they areused differently grammatically.
WithADJECTIVES
SO
So is used in frontof an adjective alone:
He’s so funny.
The day is so hot.
[So can also be used with an adverb: She plays the piano so well]
SUCH
When we havean adjective AND noun together, we use such:
He’s such a funny person.
It’s such a hot day.
Itis not possibleto usethese the other way round.
WRONG: he’s such funny
WRONG: he’s so a funny person
Remember to put the ‘a/an’ AFTER such, NOT BEFORE:
WRONG: he was a such funny guy
RIGHT: he wassuch a funny guy
However, when the noun is plural ORwhen the noun is uncountable, we
don’t need ‘a/an’:
They are such funny people.
On holiday we had such hot days.
There is such terrible pollution in this city.
He hassuch wonderfulpatience with that child.

2. WithNOUNS:
SO
We can use soin frontof a noun if we use qualifiers: much, many
There are so many placesto see in Colombia.
I’ve gotso much love to give.
SUCH
We cannot use such with many/much:
WRONG: There are such many places to see in Colombia.
WRONG: I’ve got such much love to give.
BUT we can use it with a lot of to mean the same:
There are such a lot of places to see in Colombia.
I’ve gotsuch a lot of love to give.
Such can also be used justwith a noun without an adjective and emphasises
it (remember the rules for ‘a/an’):
I have such a headache rightnow.
We felt such fools when we saw the pictures.
This is quite a formal way of speaking.
Remember ‘such as’ means ‘like’ and is different from these examples:
There are many places to see in Colombia, such as Caño Cristales, the Amazon
and the Pacific Coast.
THAT CLAUSES
You can use‘so’ and ‘such’ with a ‘that’ clause to show the result of the first
clause:
It was so hotthat I couldn’tsleep.
It was such a nice day that we decided to go to the park.