Overview
So is used before an adjective or adverb (so beautiful, so quickly) to add emphasis or express degree. Such is used before a noun phrase — usually with an adjective before the noun (such a beautiful day, such good people). Both can introduce result clauses with that (It was so cold that we stayed in / It was such cold weather that we stayed in).
So — Before Adjective / Adverb
- RuleSo + adjective or adverb (no noun)
- ExampleThe film was so boring.
- ExampleShe spoke so quickly I couldn't follow.
- ResultSo + adj + that: It was so hot that we went swimming.
Such — Before Noun Phrase
- RuleSuch + (a/an) + adjective + noun
- ExampleIt was such a boring film.
- ExampleThey are such kind people.
- ResultSuch + noun phrase + that: It was such bad weather that we stayed in.
Key Pattern
- So + adjShe is so beautiful. (adjective alone)
- Such + nounShe is such a beautiful woman. (adj + noun)
- Result thatBoth can be followed by a that-clause for result
- EmphasisBoth add strong emphasis or exclamation to a sentence
When to use
So (adjective)
The exam was so difficult that nobody finished.
Such (noun phrase)
It was such a difficult exam that nobody finished.
So (adverb)
He runs so fast that he always wins.
Such (weather)
It was such terrible weather that the match was cancelled.