"Black people get a little testy when white people call them 'articulate.'"

Notes Lynette Clemetson in the Week in Review explains why.

“Historically, it was meant to signal the exceptional Negro,” [said Michael Eric Dyson, a professor of humanities at the University of Pennsylvania.] “The implication is that most black people do not have the capacity to engage in articulate speech, when white people are automatically assumed to be articulate.”

And such distinctions discount as inarticulate historically black patterns of speech. “Al Sharpton is incredibly articulate,” said Tricia Rose, professor of Africana Studies at Brown University. “But because he speaks with a cadence and style that is firmly rooted in black rhetorical tradition you will rarely hear white people refer to him as articulate.”

While many white people do not automatically recognize how, and how often, the word is applied, many black people can recall with clarity the numerous times it has stopped them in their tracks.

What's really amazing is not that black people can speak well, but that white people haven't yet gotten the message that it's a bad idea to keep pointing it out.

NOTE: I edited the last sentence to make the point sharper.