Nouns for substances are uncountable nouns, the plural forms are reserved for 'kinds of' or 'types of'; for example:
countable
The noun 'daytime' is an uncountable noun.
The noun sheet is a countable noun. The plural form is sheets.
The noun skill is a countable noun; a skill or many skills.
uncountable
Transport is both countable and uncountable as a noun.
The noun 'steel' is an uncountable (mass) noun, a word for a substance.
Shark is a countable noun.
countable
Countable
The noun 'daytime' is an uncountable noun.
The noun 'shoe' is a countable noun, the plural form is shoes.A countable noun is a noun that has both a singular and a plural form.An uncountable noun is a singular noun that has no plural form (such as education or oxygen) or a plural noun that has no singular form (such as news or clothes).
The noun 'animal' is a countable noun. The plural form is animals.
Prawn - prawns is the plural - is a countable noun
Pasta is a countable noun
Countable
The word 'violence' is an uncountable noun.