The noun coffee is an uncountable noun as a word for a substance; units of coffee are expressed as a pot of coffee, a cup of coffee, a sack of coffee, a ton of coffee, etc. But like many nouns for substances, the plural form is used for 'types of' or 'kinds of'; for example:
This cafe has an interesting selection of coffees.
Transport is both countable and uncountable as a noun.
countable
uncountable
uncountable
Uncountable
The gerund painting is a countable noun, as in "There are 12 paintings in this room."
Coffee grounds are generally considered uncountable because they refer to a mass or substance rather than individual items. When talking about them, you would typically say "some coffee grounds" rather than "two coffee grounds." However, in specific contexts, such as when referring to distinct portions or servings, they might be treated as countable.
countable
few is countable
Countable
The noun 'steel' is an uncountable (mass) noun, a word for a substance.
he asked me if the word fire wood countable or uncountable?