Yes, the noun 'sky' is a countable noun. The plural form 'skies' is a word most often used when referring to the weather or specific atmospheric conditions.
The noun 'sky' is an uncountable noun as a word for the atmosphere that surrounds the earth.
Transport is both countable and uncountable as a noun.
countable
uncountable
Uncountable
The gerund painting is a countable noun, as in "There are 12 paintings in this room."
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."
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?
Pasta is a countable noun