I am your biggest fan! I'm starting a fan club because you speak English so good. . . . or is it well? No wait, good, right? I think . . .
Dangit! Now I forgot my question.
You're 4ever Fan!
Johnny B. Good
Dear Mr. Good,
I'm honored. Truly I am. And that's a very good question you didn't ask.
That reminds me of a story I never told. About a good well that welled water well. So well, in fact, that the welled water tasted really good. Gooder . . . er . . . I mean better than water that wasn't from a good well. And well, that good well sold well when they put it up for auction because the welled water was so good. The owner made a good profit.
Is that as clear as mud? . . . Get it?!!! Mud?! Water?!! Cause the water in the ground would make mud?!!! Oh, I do crack me up.
Alas, for real help, I must defer to Grammar Girl again. She explains this concept well. And what with the explanations of linking verbs vs. action verbs . . . well, suffice it to say, you have it on good authority that it is okay to say "I'm good" when someone asks you how you're doing. You do not, however, have my permission to say "you speak good." Ever. And I mean that.
The Grammar Nazi
P.S. Upon reflection, I wish to modify my response. When a language is invented that is called "Good," then you may say "you speak Good." Until that time, please refrain.