a. use so + adjective/adverb (e.g. so quick, so quickly) and use such + noun (e.g. such a book, such people)
b. So and such make the meaning of an adjective (or adverb) stronger (e.g. We had such a good time)
1. use so and such with the meaning ""like this"" (e.g. I didn't realise it was such an old house.)
2. so long vs. such a long time; so far vs. such a long way; so much, so many vs. such a lot (of)
Idiom 365
Tongue in cheek: humour or joke, although you might appear to be serious
Example: My comment was made tongue in cheek (TIC). Don’t take me seriously.