ADJECTIVE OR ADVERB
Definitions:
An adjective is a word or set of words that says something about a noun.
Adjectives may come before the word they refer to.
Examples:
That is a cute puppy.
She likes a high school senior.
The technology is state-of-the-art.
An adverb is a word or set of words that refer to verbs, adjectives, or other adverbs.
Examples:
He speaks slowly (modifies the verb speaks)
He is especially clever (modifies the adjective clever)
He speaks all too slowly (modifies the adverb slowly)
An adverb answers how, when, where, or to what extent—how often or how much (e.g., daily, completely).
Examples:
He speaks slowly (answers the question how)
He speaks very slowly (answers the question how slowly)
Taste, smell, look, feel, etc., that refer to the senses are not followed by -ly
Examples:
Roses smell sweet.
The woman looked good. (appearance)
The woman looked angrily at the driver of the bus.
She feels bad about the news.
She is not feeling with fingers, so no -ly.
You smell good today. (your perfume)
Finally I can smell good/well again. (With your own nose)
You do not look well today. (In health you use well.)
I don't feel well, either.
Many adverbs end in -ly, but many do not. Generally, if a word can have -ly added to its adjective form, place it there to form an adverb.
Examples:
She thinks quick/quickly.
How does she think? Quickly.
She is a quick/quickly thinker.
Quick is an adjective describing thinker, so no -ly is attached.
She thinks fast/fastly.
Fast answers the question how, so it is an adverb. But fast never has -ly attached to it.
We performed bad/badly.
Badly describes how we performed, so -ly is added.
There are three comparative degrees of adverbs. In formal usage, do not drop the -ly from an adverb when using the comparative form.
Incorrect: She spoke quicker than he did.
Correct: She spoke more quickly than he did.
Incorrect: Talk quieter.
Correct: Talk more quietly.