In the crusade against flabby writing, we're often counseled to get rid of redundancies with a machete. We are to show no mercy for the likes of repeated ideas and words. But following this "rule" blindly, as with following any rule blindly, can result in text that fails to get its meaning across. There are times when redundancy is a boon to the text rather than a scourge.
Critics are quick to denounce redundancy, but they're not as quick at pointing out its usefulness.
Language has redundancies built in to its grammar. These redundancies are such a part of language that we don't think of them that way. No one would argue against the usefulness of matching a singular subject with a singular verb in a sentence, yet this is a type of redundancy. Nor is anyone likely to take offense at those boys, another redundancy. That's the way language works. It marks such things as number more than once to ensure understanding, even if part of the message is missed.
That's the key to any useful redundancy: ensuring something important isn't missed, even if part of the message is.
New ideas, complex directions or thoughts, and important information are all cases in which a little redundancy can help meaning get across.
Mix together the brownie mix, 2 eggs, 1/2 cup oil, and 1/4 water.
Although mix together is redundant, it helps ensure the reader knows what to do, even if they skip over the first word. It's a common phrase in recipes. While mix could do the job on its own, together serves as emphasis, essentially saying, "Hey, don't miss this bit! It's important!"
But as we've been taught, redundancy can bury the message as easily as it can emphasize it. Put too many words in a sentence and the reader might wonder where the subject and verb are in all of it. Such redundant words are called pleonasms. You can remove a pleonasm from a sentence without changing the meaning. In fact, the meaning will probably stand out clearer. Consider:
Unless and until politicians in Washington have the courage to tackle runaway entitlement programs, no president … is going to put a dent in the deficit. —USA Today (2012)
Which is it: unless or until? While unless means "except under the conditions of" and until means "before a specific time," in this case, there's not much meaning difference. Either way, according to the sentence, the deficit won't get better without the entitlement programs being fixed. Choosing unless or until will provide the sentence with more punch:
Until politicians in Washington have the courage to tackle runaway entitlement programs, no president … is going to put a dent in the deficit.
Many resources offer lists of common redundancies to watch for. Garner's Modern American Usage lists these, among many others:
plead a plea
visible to the eye
Amy Spencer, tweeting as @EditUnited, frequently features redundancies she's found in her editing. Some of my favorites are:
future leaders of tomorrow
toward the direction of
This type of redundancy restates the obvious rather than restating the important. Readers may need to grasp your meaning, but they don't need to be talked down to. Fixing these redundancies should be a matter of course.
(Mostly) Harmless Redundancy
Some redundancies have been used so often that we cease to recognize them as such:
pick and choose
We use these phrases so often that they've become idiomatic. In your writing, these phrases are, as Douglas Adams might say, "mostly harmless." You can edit them to tighten your writing, but if you leave them, no one will think less of you (except maybe those critics who have completely lost touch with real language usage; feel free to ignore those critics).
Generally, stopping to consider what a word actually means will help you spot redundancies. Considering how important that redundancy is to meaning will help you decide if it should stay in the sentence or go.