Select the option that corrects the error in the given sentence. She sings good.

Correct — D. Sings is a verb, and a word that modifies a verb has to be an adverb. Good is an adjective, so it can describe only a noun — a good singer, a good voice.

The adverb of good is the irregular form well, which takes no -ly. The sentence must read She sings well, and option (d) supplies it.

Nothing else is wrong. The subject, the tense and the agreement are all sound, and only the manner word needs replacing.

Why the others are wrong

• (a)
  better — Better is the comparative of well. But the sentence's only fault is the adjective good where an adverb belongs, so the fix is the plain adverb — changing the degree as well would add a comparison the sentence never makes.
• (b)
  goodly — Goodly is a real but archaic word meaning considerable in size or amount, as in a goodly sum. It is an adjective, and it is not the adverb of good.
• (c)
  best — Best is the superlative of well. It is the right word class, but nothing here asks for a ranking: the single fault to be corrected is good → well, so the positive degree is what fits.

The rule is about word class, not about which word sounds better.

An adjective modifies a noun or a pronoun. An adverb modifies a verb, an adjective or another adverb. Sings is a verb, so the modifier must be an adverb.

Most adverbs of manner are made by adding -ly to the adjective: quick becomes quickly, careful becomes carefully. Good is irregular and its adverb is well.

The exception worth learning is the linking verb. After be, seem, look, feel and taste, an adjective is correct — the soup tastes good, she looks good — because the word describes the subject, not the action.

Key facts

• An adverb modifies a verb, an adjective or another adverb, while an adjective modifies a noun or a pronoun.
• The adverb of good is well, an irregular form that does not take -ly.
• Well is also an adjective when it means in good health, as in She is well again.
• After a linking verb such as be, seem, look or taste, an adjective is correct: the soup tastes good.

Common traps

• Choosing better, which is the right word class but the wrong degree, because it sounds more polished
• Carrying informal spoken usage into the exam, where she sings good is marked wrong

No directly related past PYQ was found.