We can use so and such meaning “very” or “really” to emphasize positive and negative situations. Let’s take a look:
So + adjective / adverb
👉 My students are so nice (tan majos)
👉 You can run so fast
👉 I was so tired that I fell asleep in the armchair
Such a/an + adjective + countable singular noun.
👉 My friend is such a nice person (es tan majo)
👉 This is such an expensive flat (es tan caro)
Such + adjective + uncountable or plural nouns
👉 My friends are such nice people (son tan majos)
👉 It was such awful food (fue tan mala)
We can use either structure with the same meaning. Let’s have a look at some examples
👉 They are so generous → They are such generous people
👉 New York is so big → New York is such a big city
👉 The food is so expensive → It’s such expensive food