I was watching a science program last week and one of the people being interviewed mentioned “mutual cooperation.”

“Mutual cooperation.” Can be any other kind of cooperation? Can there be unilateral cooperation?

“Mutual cooperation” is yet another example of a pleonasm; that is, using more words than necessary to express an idea. (For more on stamping out redundancy, see these posts: “Redundancies: Does it bear repeating?” and “Cutting unneeded words: pleonasms.”)

Granted, the phrase “mutual cooperation” was said in an extemporaneous discussion, and I’m not about to criticize someone for minor usage errors in their daily speech. Unrehearsed speech, such as conversation, is like a first draft. (And you know what I think of first drafts.) It can be messy, littered with (among other things) ums, ahs, you-knows, run-on sentences or sentence fragments, and yes, repetition.

If we’re not careful, redundancies—along with other usage and grammar errors—sneak from our speaking to our writing. “Write the way you speak” is common advice. And it’s good advice. But don’t forget to review what you write, or those sneaky little errors will make your writing less effective.