Good is common as an adverb in informal speech, especially after forms of do: He did good on the test. She sees good with her new glasses. This use does not occur in formal speech or edited writing, where the adverb well is used instead: He did well on the test. She sees well with her new glasses.
The adjective good is standard after linking verbs like taste, smell, look, feel, be, and seem: Everything tastes good. The biscuits smell good. You're looking good today. When used after look or feel, good may refer to spirits as well as health: I'm feeling pretty good this morning, ready to take on the world. Well is both an adjective and an adverb. As an adjective used after look, feel, or other linking verbs, it often refers to good health: You're looking well; we missed you while you were in the hospital. See also bad.

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