Personally, I try to speak and write impeccable English. I try to capitalize proper nouns, get punctuation correct, use parallel form, and employ precise verbiage. (I'm also a fan of the Oxford comma, can you tell?)
As a programmer, I put an equivalent amount of effort in the code I write, as code is read many more times than it is written. I pay close attention to style guides, use direct clear idioms, and try to follow recognized best practices. If I were looking for others to work with, I'd be looking for the same.
My question is: is careful usage of human language a trait that correlates with better code? If so, could human resource personnel use this to good effect to screen out applicants, or would they be reducing their qualified applicant pool arbitrarily?