Although we often think of English and math as being two very different worlds, there is one way in which they are alike. In math, when you multiply a negative number by a negative number, the resulting number is positive. This rule also applies to English.
A negative and a negative in a sentence generally create a positive.
This can drastically change the meaning of a sentence and cause confusion.
How a Negative Word Works
When you use a negative, you are implying the absence of something:
“Joe doesn’t have any clean socks.”
The message is clear: it’s time for Joe to do laundry. But when you add an extra negative, it actually creates a positive and changes the meaning of the whole sentence.
“Joe doesn’t have no clean socks.”
Well, if Joe doesn’t have no clean socks, then that means Joe does have some clean socks. Maybe laundry can wait.
Double negatives can sometimes sneak their way in just from casual use when people momentarily forget to use grammar rules. Maybe you are talking with your friends and one of them says:
“I didn’t have no time for breakfast this morning.”
Well, if they didn’t have no time, then they had some time and they should have eaten. That friend might go on to say:
“I can’t do nothing about it if I keep waking up late.”
Right, but that friend could do something about it if they cannot do nothing.
Notice in these examples that those extra negatives sneak into the sentences in the form of contractions. Can’t, don’t, won’t, or any word ending with -n’t means there’s a not stuck on the end. Although it can be easy to let these double negatives slip into casual conversation, they make it confusing to determine what is actually meant. That’s why it’s important to be aware of your use of negatives and to avoid double negatives in a sentence. Don’t be no lazy grammarian.
Even Sneakier Prefixes
Sometimes double negatives are inadvertently used because another negative is hidden in the prefix, so adding another one isn’t necessary. This kind of unnecessary usage tends to “clog up” a sentence and a reader or listener is left trying to figure out what the real meaning is. For example:
“The cost of her wedding dress is not insignificant.”
Instead of plowing through all of those negatives to figure out that her wedding dress was pricey, cut to the chase and be more succinct by stating:
“Her wedding dress was expensive.”
“The cost of her wedding dress was significant.”
But, if money is no worry, then:
“The cost of her wedding dress is insignificant.”
One Exception to the Rule
What about two negatives working together in a sentence? It is possible. One way this is done is through the pairing of neither and nor.
“The student had neither his homework nor his pencil today.”
“Mary wanted neither the chicken nor the fish option.”
But when extra negatives accidentally get stuck in there, the whole thing changes:
“The little girl did not know neither her last name nor her phone number.”
What? Too much negativity! This one could be corrected by writing either of these, instead:
“The little girl did not know either her last name or her phone number.”
“The little girl knew neither her last name nor her phone number.”
And, Maybe, Another Exception
Sometimes intentionally using double negatives is a way to soften the intensity of what is being suggested.
“Isn’t the new guy at work cute?” “Well, he’s not unattractive.”
“I can’t not cry when I see that puppy commercial.”
(Warning: the waterworks will be close by if that commercial comes on!)
Or, if you’re just sort of prepared for something:
“Well, I’m not exactly unprepared.”
Purposefully using double negatives, and doing so correctly, can skirt the negative transforming into a positive issue, but most of the time, when double negatives are used in a sentence, it is a grammatical mistake.
As the boys of Pink Floyd proudly proclaimed, “We don’t need no education!” But maybe just a quick lesson in double negatives wouldn’t hurt?