The English words good and well are often confused by native and non-native speakers of English – this is a good lesson that will put you well on your way to understanding the difference.
Good is an adjective, which means that it modifies nouns.
This is a good movie
What a good idea!
You speak good English
Good can be used with copular verbs (that is, verbs which express a state of being, such as to be, to seem, and to appear), but it is still an adjective modifying a noun, not a verb.
This movie is good
His ideas are good
Your English is good
Well is an adverb, which means that it modifies verbs, adjectives, and other adverbs.
Did the movie do well at the box office?
It was a well-defined idea
You speak English well
Well can be used as an adjective to mean "in good health."
You look well
I don’t feel well
The Bottom Line
The confusion between good and well comes from their similar meanings, and a general confusion between adjectives and adverbs. Take a moment to think about what the word is modifying: if it’s a verb, you’d do well to use well; otherwise, the good choice is good.
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