What are examples of nouns that are both countable and uncountable?
Agreement, Light, War, Space, decision, noise, bone, cloth and many-----
Some nouns are countable and uncountable nouns in English, but keep in mind it might not in other languages the same.
That is why we must learn English by their ways only.
Like we mean a general situation some nouns are uncountable noun.
Like, I have good agreement ( abstract ) with Socratic to contribute time to time.
It is in general a situation.
We made an agreement to run the organization with Government last year.
It means a SPECIFIC issue that made the agreement a countable noun.
Hope it works.