Here, the first coffee is a non-countable noun note it is preceded with much , but the second is a countable noun note it is preceded by a.
It follows therefore that a noun phrase functions as a noun in a sentence.
Rules: These are not suffix rules.
The meanings of and secretive largely overlap; however, silent implies a habit of saying no more than is needed.
Anon In this example, there is a noun phrase within a noun phrase.
All this talk about secret-keeping reminds me of the concept of the secret-keeper in the Harry Potter books.