Question of question

it is a quaint question.

Usually, when I would like to indicate the part of speech of a word, I would say

"turn" is a linking verb.

"car" is a noun.

"pretty" is an adjective.

However, but sometime when I am writing and thinking at the same time, I would write

"turn" is linking verb.

"car" is noun.

"pretty" is adjective.

When I just want to refer to the type of a word in a general way, is it correct to omit the article?

Thank you.