Never use a double negative
There are many rules of grammar we are taught in childhood that stick with us when we become adults. We may not remember the why, but we remember the what.
But not all rules are really rules. Some are misremembered. Some mistaught. Others misapplied.
They stay in our minds and colour how we use language through life. How we use language incorrectly.
These rules are:
The Seven Sins of Syntax
The Sin
Flying in the face of what we are told about two wrongs not making a right, we are taught that two cannots do make a can. Taken literally, a negative reverts a positive. Adding another negative will cancel out the first negative. This leaves you with the original positive.
It is considered a sin to use a double negative largely because doing so seems illogical. It is an example of pleonasm: using more words than is necessary to convey an idea.
This is most relevant when the negatives used include a verb and a noun. When both are negative, the sentence can have a different meaning to the one you intended to convey.
For example:
I don’t have no money.
You may mean you have no cash, but the sentence says you do.
You aren’t saying nothing,
This may be intended as a threat to keep quiet, but you’re actually telling someone to speak.
Not So Sinful
Life is not all black or white. Not everything is can or cannot.
A double negative can be used to modify a single verb to show that the action being carried out is less certain.
If I tell you:
I’m not going to the party.
you know you won’t see me there.
If I tell you:
I’m not not going to the party,
it may mean that I am going but going later. Or that I won't be staying long. Or perhaps that I will go but have no intention of speaking to the host. It is riddled with implication.
The double negative can also work when modifying a negative adjective. It creates a grey area between point a and point b.
For example:
I’m not unhappy (or I’m not not happy),
doesn’t tell you that I am happy. It just says that I am not suicidal. As such, the double negative here communicates something much more realistic about mood.
I’m not unsympathetic (or I’m not not sympathetic),
says that while I understand the predicament, it won’t have any impact on the decision I make or the action I take. A phrase heard often by Customer Service Agents who want to appear helpful whilst actually being anything but.
Committing More Sins?
Using double negatives with intention to create that grey area is perfectly acceptable.
But a negative verb with a negative noun is generally still frowned upon, even though it is common syntax in several dialects.
Primarily this is because it is likely to alter your meaning so may cause confusion. This ain't no grammar snobbery. Or rather, it really ain't grammar snobbery.
