a. One has to work hard to be a successful person.
b. Vasant seldom comes to see his aged parents.
c. I some × feel that I have done nothing important in my life.
d. One has to walk fast in the treadmill-test.
The underlined words in the above sentences are __________.
Answer options :

The correct answer is Option D (Adverbs).

Key Points:
• This question evaluates the candidate's ability to identify Parts of Speech contextually, a crucial grammatical concept frequently tested in MPSC and other competitive examinations.
• Option 4 is the correct answer according to the official MPSC answer key. The underlined words—'hard', 'seldom', 'sometimes', and 'fast'—all function as adverbs in their respective sentences. They modify verbs by answering how or how often the actions occur.
• Let us analyze each sentence: In (a), 'hard' modifies the verb 'work' (adverb of manner). In (b), 'seldom' modifies the verb 'comes' (adverb of frequency). In (c), 'sometimes' modifies the verb 'feel' (adverb of frequency). In (d), 'fast' modifies the verb 'walk' (adverb of manner). None of these modify nouns, ruling out adjectives. They do not link clauses or show positional relation, ruling out conjunctions and prepositions.
• A common MPSC trap is confusing words like 'hard' and 'fast' for adjectives because they share identical forms, but their function (modifying a verb vs a noun) determines their classification.
• Always observe what grammatical element the word modifies before labeling it.
• Key Takeaway: Remember: Words like 'fast' and 'hard' act as adverbs when modifying verbs, and as adjectives when modifying nouns.