Living in the age of text, as we do now (the word is even a verb), it's easy to believe that our written English language is the English language, full stop, and that the English that comes out of our mouths is just a messy, inconvenient stopgap until we find a pen and jot it all down. Because text is so much simpler to deal with than oral language (being nicely packaged in 26 letters, easily referenced and indexed, and amazingly portable), we pay it a disproportionate amount of attention. But to linguists, putting text first and speech second results in a skewed view of language—it's as if laypeople...