If you are saying that english is “good,” I agree-both with your sentiment and with your assertion that good is the proper adjective for the word english. However, if you’re talking about how english is spoken, written, heard, etc., those would require adverbs to describe, such as “well” as opposed to “good.” For example, how are you? I am well.
(How where when why) are adverbs that answer the question.
Now be good!
And be well...
Adverbs work on action verbs such as "speak". She speaks quickly.
I speak good English, not the English of London or Sydney or SE D.C. I also speak English well, not poorly.
Back to beer, brats, and the ball game. Have a good weekend!