Good and well is another pair of words that seem to confuse many people. And there’s a reason for that: they are confusing, even to me!
First Understand, What Are You Describing?
The key to determining which word is correct is based on usage.
Good is an Adjective
Good is an adjective. Adjectives describe nouns (persons, places or things.) So for example: You would never say “Well afternoon, Mrs. Jones,” would you? No, you would say, “Good afternoon, Mrs. Jones.” In this case “good” describes the afternoon you are wishing Mrs. Jones.
Well is an Adverb
Well, however, is an adverb and therefore describes how an action was done.
For example: “You presented very well today under enormously stressful circumstances.”
“You handled that hostile customer very well.”
The Confusing Part: Every Day Speech
But what about all those times someone asks you “how are you doing?” Most of us say “I’m good,” or “Good, thank you.” And this is perfectly fine.
Good, in this case, is describing you, or your state of being.
However, if you had been sick, and someone asks you how you are doing, you can safely assume they are referring to the state of your health. In this case, you should say “I’m doing well, now, thank you.”
Good and well are another pairs of words that need some thought and practice to master: but once you do, you’ll write very good, er, I mean very well!