I love grammar books. Since I was a very young learner of English language back in Hong Kong, then a British colony, I kept a copy of Concise English Grammar published by Macmillan. In college, freshman reading and writing class required On Writing Well by William Zinsser. These books have served me well when I need quick reference on grammar and style. My latest addition is the cocktail menu-sized Style & Circumstance: The Gentleperson’s Guide to Good Grammar by Phineas J. Caruthers. It covers all the grammar essentials well enough—subject/verb agreement and syntax especially, and it has a serviceable index. This book addresses how to use each part of speech, as well as simple and complex sentences. It also discusses things like voice, lyricism, and rhythm. I like the section on creating more sophisticated sentences. Style & Circumstance would be a precious addition to e-book for quick reference on language usage.