The word 'fast' in the sentence
'He is a fast writer' is

Correct option is D

Solution: Correct Answer is (d) an adjective.
Explanation:
In the sentence "He is a fast writer," the word ‘fast’ describes the noun ‘writer’ — it tells us what kind of writer he is (a quick or speedy one).
Since adjectives are words that describe or qualify nouns, ‘fast’ functions here as an adjective.
Information Booster:
→ The word ‘fast’ can play different roles depending on the sentence.
Adjective: Describes a noun → He is a fast runner.
Adverb: Describes a verb → He runs fast.
Verb: Rarely, can mean to abstain from food → They fast during festivals.
Additional Knowledge:
→ To identify an adjective, ask the question “What kind?”, “Which one?”, or “How many?” about the noun.
Here: What kind of writer → Fast writer → So ‘fast’ is an adjective.