Over the years, I’ve learned a lot about English grammar and usage — most of which I promptly forgot. And not for lack of use. Every day I apply what I’ve learned to catch and fix writers’ mistakes.

Although English-language verbs generally don’t inflect or change in form to agree with the subject in number, they do so in the present tense, third-person singular.

For more than a millennium after the fall of Rome, educated Europeans were distinguished by their knowledge of Latin. One of the three subjects of the trivium—the basic tier of a classical education, ...