by themselves don’t mean anything.
… when used before an adjective or adverb they give more information about how the speaker feels.
… they are close in meaning to very.
… so goes directly before an adjective.
It is so hot.
He is so fast.
This book is so interesting.
These cookies are so delicious.
… such goes between a verb and the article (a, an) preceding an adjective-noun combination.
He is such an annoying man! => He is a very annoying man!
It is such a funny film that I’ve watched it many times.
She always takes such a long time to answer her emails => She takes a very long time to answer them.
LOOK OUT! An adjective or adverb goes immediately after so. We use a or an and a noun immediately after such though.
It is so expensive.
It is such an expensive car.
=> So and such mean ‘very’.
=> They cannot be used alone.
=> Both are used to express our feelings about something.