I enjoy reading Steven Pinker's popular non-fiction (see here, here, here). This one I've had on my shelf for awhile; published in 1999, I picked up this UK edition on the $3.98 remainder table at Barnes & Noble a few years later. Finally percolated to the top of the cybernetic to-be-read pile.
Pinker's research area is broad: roughly, how language is processed and generated by the brain. (He's written elsewhere on even broader topics.) Here, he concentrates on how that process is illuminated by the study of irregular verbs and nouns. (Consider your average dictionary, packed with verbs; you might be surprised (as I was) to learn that only a couple of hundred of them are irregular. Seems like more.)
Pinker argues, based on his research, that "language comprises a mental dictionary of memorized words and a mental grammar of creative rules." This is contentious, but Pinker does a good job defending it. Still, it's worth remembering that he's not a dispassionate observer.
As usual, Pinker tells his story with verve, clarity, and occasional humor. (He likes to illustrate points with relevant newspaper comic strips.) I laughed out loud at this, after he's described one of his research studies apparently carried out in a University-attached community:
We also wondered whether the effect might be a fussy affectation of pointy-headed, Volvo-driving, endive-nibbling, chablis-sipping young urban professionals.
Pinker does get down into his research weeds occasionally; I don't know how many readers will be interested in exactly how a subset of Hungarian irregular nouns get declined differently when they are used as proper names. But this is proceeded by a pretty good joke ("That fact, combined with the disproportionate number of Hungarian mathematicians and scientists, led one physicist to suggest that Hungarians are a advanced race of space aliens, but that theory is no longer widely believed.") Readers can pick and choose what to delve into and what to skim over.