Double Negation in English
There was a recent thread by Cogumela which invoked many responses. I read them and thought about the question, which was quite interesting, and I was prompted to publish my conclusions. The thread was prompted by this example:
You can say that, but very few people seldom do.
A horrible example of the misuse of language if there ever was one.
Of course, a "horrible example of the misuse" could be an example of the very problem exhibited by the original sentence. Does this mean a good example of a misuse, or a bad example of a misuse? Is this a double negative or not?
Returning to the original question (the paragraph above is just a little joke), Cogu's example is, in fact, a double negative. There are several types of double negation, and Cogu's example follows the pattern of "Words negative in meaning but not in form." Examples include seldom, rarely, hardly any, very few, etc.
Logically, to say that "very few people seldom do" implies that many people often do, because double negatives in English cancel each other out. But the writer intended the opposite, or he wouldn't have said it so weirdly.
I believe this explains why the sentence is so strange.
4 Answers
Then there's the famous G W Bush quote, "they misunderestimated me"... 
I agree that "a horrible example of the misuse" is also a double negative.
The original sentence is a great example of the way in which language is misused and abused. Or it is a horrifying example of how language is routinely abused. On the other hand, the sentence is a horrible example of what would pass for proper use of the language by a (presumably) native user.
Pure double-negatives have the logical effect of cancelling out, making the meaning positive.
Cogu's case, however, was one of double "limiters", such as "few people" and "seldom". Combining those does trend positive, but not a full case of "cancelling out".
If I said, "few people are seldom wrong" it could literally mean that only a few people are occasionally right. Not a pure double-negative, as I said.
We think of grammar as being a codified set of rules, but at some point grammar becomes a hypothesis, based on analysis and interpretation. You can conceive of Cogu's example as using limiters, but you can also conceive of limiters as being "negative in meaning but not in form."
If I said, "few people are seldom wrong" it could literally mean that only a few people are occasionally right. Not a pure double-negative, as I said.
That was my point. Double negatives, as well as "limiters" or "negatives in meaning but not form", do cancel each other out, at least in English. Double limiters in English work (or don't work ) the same as full blooded double negatives.
