The Principal Problem

Wendalyn Nichols, editor of the Copyediting newsletter, offers useful tips to copy editors and anyone else who prizes clear and orderly writing. Here she looks at the all-too-common confusion of principal and principle.

I've learned that I cannot expect my child's teachers to spell well. (That one of them cheerfully refuses to engage in self-flagellation over this moral failing still irks me, though.) But I did think that editors were people who could be relied upon to fear the discerning reader's scorn. I know that English spelling is a mess and that remembering the rules is easier for some than for others, but you'd think someone who was a weak speller but who worked with text every day would be aware of his or her particular weaknesses and be on the lookout for them.

This assumes, of course, that the person is even aware of the problem.

The object of my derision in this case is the person who left a script for an educational video (a component of an English-teaching course) on one of our copy machines at work. At the beginning of the document is a paragraph with instructions for casting the video, followed by the dialogue between the "principle character" and the "secondary character."

I leafed through the pages to check whether the first use of principle was a typo, but nope. The -le spelling was used throughout the document.

Principle and principal are homophones, so it's not hard to see how they can be confused. But just as we must distinguish orthographically between they're, their, and there, we must use the correct form, principle or principal, according to context.

Both words come from the Latin princeps ('leader' in the sense of 'initiator'), but from two different Latin derivatives: principalis 'chief, leading' and principium 'beginning'. It would have helped if an l hadn't wiggled into the spelling of the latter somewhere between Middle French principe and Middle English principle, but we're stuck with it. Today, we need to resort to mnemonic tricks to help us with the difference.

The first thing to remember is that principle cannot be an adjective. It is only a noun, so if you find yourself wanting to describe something, use principal instead. It can help to think of the -le ending of principle as matching the -le of rule.

In contrast, principal is most often an adjective (A for adjective, A in -pal), as in "the principal character." The noun uses are mainly restricted to two narrow contexts: for certain leadership roles, such as the principal of a law firm or a school (for which you can dredge up the grade school memory trick "The principal is my pal"); and for a sum of money that earns interest (for which you can try to remember that it is from the adjectival use "principal sum").

Wendalyn Nichols is the editor of the Copyediting newsletter and a commissioning editor of dictionaries for Cambridge University Press. She began as a freelance researcher, writer, and editor, then became a lexicographer and editor with the Longman Group. For four years she was the editorial director of Random House Reference and Information Publishing. She lives in New York, New York with her husband and young daughter. Follow her on Twitter @WendalynNichols and @Copyediting.