Rule #1: Adjectives modify nouns; adverbs modify verbs, adjectives, and other adverbs.

You can recognize adverbs easily because many of them are formed by adding -ly to an adjective.

Here are some sentences that demonstrate some of the differences between an adjective and an adverb.

Here careless is an adjective that modifies the proper noun Richard.

Here carelessly is an adverb that modifies the verb talks.

Here happy is an adjective that modifies the proper noun Priya and extremely is an adverb that modifies the adjective happy.

Adverbs can't modify nouns, as you can see from the following incorrect sentences.

The correct sentence above should say, "He is a quiet man."

The correct sentence above should say, "I have a happy dog."

Rule #2: An adjective always follows a form of the verb to be when it modifies the noun before the verb. Here are some examples that show this rule.

Rule #3: Likewise an adjective always follows a sense verb or a verb of appearance — feel, taste, smell, sound, look, appear, and seem — when it modifies the noun before the verb.

Here bad is an adjective that modifies the noun cough. Using the adverb badly here would not make sense, because it would mean her cough isn't very good at sounding.

Here awful is an adjective that modifies the noun oil. Using the adverb awfully here would not make sense, because it would mean that castor oil isn't very good at tasting.

Here fresh is an adjective that modifies the noun air. Using the adverb freshly here would not make sense, because it would mean that the air has a sense of smell that it uses in a fresh manner.

Here unhappy is an adjective that modifies the pronoun she. Using the adverb unhappily here would not make sense, because it would mean that she isn't very good at seeming.

Be careful to notice whether the word modifies the subject or the verb in the sentence. If the word modifies the subject, you should use an adjective. If the word modifies the verb, you should use an adverb. The difference is shown in the following pair of sentences.

Here sweet is an adjective that modifies the noun apple. Using the adverb sweetly here would not make sense, because it would mean that the apple can smell things in a sweet manner.

Here carefully is an adverb that modifies the verb smells. Using the adjective careful here would not make sense, because it would mean that the dog gives off an odor of carefulness.

Avoiding Common Errors

Bad or Badly?

When you want to describe how you feel, you should use an adjective (Why? Feel is a sense verb;see rule #3 above). So you'd say, "I feel bad." Saying you feel badly would be like saying you play football badly. It would mean that you are unable to feel, as though your hands were partially numb.

Good or Well?

Good is an adjective, so you do not do good or live good, but you do well and live well. Remember, though, that an adjective follows sense-verbs and be-verbs, so you also feel good, look good, smell good, are good, have been good, etc. (Refer to rule #3 above for more information about sense verbs and verbs of appearance.)

Confusion can occur because well can function either as an adverb or an adjective. When well is used as an adjective, it means "not sick" or "in good health." For this specific sense of well, it's OK to say you feel well or are well — for example, after recovering from an illness. When not used in this health-related sense, however, well functions as an adverb; for example, "I did well on my exam."

Double-negatives

Scarcely and hardly are already negative adverbs. To add another negative term is redundant, because in English only one negative is ever used at a time

Sure or Surely?

Sure is an adjective, and surely is an adverb. Sure is also used in the idiomatic expression sure to be. Surely can be used as a sentence-adverb. Here are some examples that show different uses of sure and surely. Adjectives are in blue and adverbs are in red.

Here sure is an adjective that modifies the pronoun I.

Here surely is an adverb that modifies the adjective ready.

Here sure to be is an idiomatic phrase that functions as an adjective that modifies the pronoun she.

Here surely is an adverb that modifies the verb has been.

Real or Really?

Real is an adjective, and really is an adverb. Here are some examples that demonstrate the difference between real and really.

Here really is an adverb that modifies the adverb well.

Here really is an adverb that modifies the verb phrase going out.

Here real is an adjective that modifies the noun problems.

Near or Nearly?

Near can function as a verb, adverb, adjective, or preposition. Nearly is used as an adverb to mean "in a close manner" or "almost but not quite." Here are some examples that demonstrate the differences between various uses of near and nearly.

Here neared is a verb in the past tense.

Here nearly is an adverb that modifies the verb finished.

Here near is an adverb of place that modifies the verb crept.

Here nearly is an adverb that modifies the verb related.

Here near is a preposition. The prepositional phrase near the end of the movie modifies the noun scene.