Good and well are very often misused by both non-native and native English speakers.  Understanding the difference between good and well will enable you to use them in the right way.

Good and well – what’s the difference?

Good is an adjective, and sometimes a noun.
A good movie.
He did a lot of good when he built the school.

Well is usually an adverb.
She plays the piano very well.
The essay is well written.

The word good follows linking verbs such as a, the, be, feel, appear.
This was a good year for peaches.
It feels good to be home.

 “I’m Good” or “I’m Well”?

If you are new to the English language, you may have difficulty with the correct answer to ‘How are you?’  Do you say “I’m good”, an answer that is given a lot of late, or “I’m well”?   Some grammar purists may give you a funny look if you say “I’m good.”,  because they look at the word good as an adjective.  Adjectives do not modify verbs, and so they believe the grammatically correct way to answer is to say” I’m well”. But, “I’m good” is as grammatically correct as “I’m well.”  One needs to go to the dictionary and actually look up the meanings of the words, good and well,
 good (adjective): such as should be desired or approved, right, satisfactory; sound, unimpaired; not depressed or dejected.
well (adjective): in good health; free or recovered from illness; in a satisfactory state or position.

You can see why the belief that “I’m good” is incorrect. According to this belief, “good” is an adjective and can therefore not modify the verb “am” (since I’m = I am). However, this would mean that “I’m well” is also incorrect, since the adjective definition of “well” is the intended meaning behind the response.  The above definitions show that in fact neither words are being used here strictly correctly and, that being so, both words, good and well, are acceptable.

Feeling good and feeling well

Then there is the debate about the difference meanings that are conveyed when you say “I feel well” and ” I feel good”.  Here is a  guide from to the usage of good and well in this context:
“Today virtually everybody agrees that both good and well after ‘feel’ and’ look’ are predicate adjectives. The years of disagreement over which was correct seem to have contributed to some differentiation. Look well and feel well tend to express good health. Feel good can express good health or it can suggest good spirits in addition to good health. Look good does not generally refer to health, it relates to some aspect of appearance.” Merriam-Webster’s Dictionary of English Usage, 1994

Understanding the difference between good and well will enable you to use them in the right way in the appropriate context.