In English class, you should have heard the line “Avoid using double negatives” from your teacher.
Well, if you haven’t, you’re reading what it is about right now so don’t worry.
So what is a double negative?
Two negative expressions, or words in the same sentence is a double negative. The two negatives usually cancel out each other and you end up with a net positive, the opposite of what the speaker/writer intended.
Just like in basic Math, where a negative number multiplied by another negative becomes positive. e.g.: -1 x -7 = 7
Such as it is, standard English, in most cases does not permit using two negative words in one clause. The only times double negatives get permitted for use are:
1. When both negatives are logically required because each is negating something different.
“We can’t not take this bus or we will be stuck here for the whole night.”
This sentence can be translated as: We can not ‘NOT take this bus’ -> We must take this bus
2. When the word ‘not’ is combined with a negative prefix and it has the effect of producing a weak or polite positive.
“I am not inclined to disagree.”
Double negatives fall into two categories, one being the cases where the meaning is emphatically negative, and the phrase is common in many varieties of the language (though considered non-standard), as in “I ain’t done nothing,” and the other being the cases where the meaning is rhetorically positive and the construction is part of standard English, as “You can’t not respect their decision.
In conclusion, just try to avoid double negatives in your sentences as much as you can and turn most of your sentences to positive form when you write or speak. This helps you make your words more clear and sharp.
He was not very often quick to catch on. -> He was often slow to catch on.
Lopez did not think that studying musical history was a good way to pass time. -> Lopez thought that studying musical history was a waste of time.
It was hard to think the group would arrive in time. -> It was thought that the group would arrive late.