I have been a professional writer for over twenty years. I have Bachelor's and Master's degrees in English. What you've stated there simply isn't true. Double negatives are frequently criticized in formal writing because they're frequently clumsy--poor usage--but if some teacher told you in "modern standard English" there is a "formal rule" stating that double-negatives revert to positives then you have been done the injustice of terrible teaching. Meanwhile, if you want to persist in this, I invite you to prove me wrong with a direct citation from the current edition of any respectable standard style guide (Chicago, MLA, or APA).
Is the Camebridge dictionairy sufficiently respectable to convince you? It is grammaticly wrong to use double negatives like "I ain't got no time" to imply a negative in English. It is however, super common to do it in various regional dialects. And since double negatives are fairly common in the various American dialects (especially the more southern ones according to a quick look on google scholar), and American culture kinda dominates worldwide with Hollywood and what not, it's become more or less an accepted "mistake" in less formal settings (e.g. books, movies) though I have yet to see it in a formal setting (e.g. school texts, scientific works). Give it a couple 100 years and it might become generally accepted again in "standard" English (based on what I could quickly find on google scholar it seems to have been generally accepted in early and middle Germanic languages, but it's largely been pushed out since.)
Given that the Cambridge Dictionary citation you provided says exactly what I said--that it is frowned upon in formal usage--I don't see your point. The linked page you've provided there says absolutely nothing about double-negatives indicating a positive.
I posted it here because I thought this thread had a long running tradition of gnome pictures. (plus I reserve the Thread of Random Randomness for my better stuff)
Formal use is generally the standard for the "correct" form of a language. The fact that certain groups of people, or regions, develop their own dialects and use that in an informal setting does not make it grammatically correct until those dialects develop enough to be considered their own language or become widespread enough to be considered part of the formal parent-language. Here's another by Yale, pointing out a negative concord is only used in various dialects but would be incorrect standard English and giving the corresponding "translation" from dialect to standard English for certain examples. And the wikipedia page, which goes quite in depth about the various types of double negatives that can be constructed and what they grammatically mean in standard English (as well as some other languages). And before you object to using wikipedia as a source, there are citations at the bottom. Unfortunately the good ones for English, like for example this one, are hidden behind a paywall. Plus, it makes a nice summary instead of having to piece together a handful of dense scientific papers/books, so that's always nice.
I think one of my most hated examples of this is people who say "I don't disagree". For me, this is a ridiculous statement that means genuinely NOTHING.
Funny, as i find that kind of expression useful. To me, it means that you agree on a general level, but you don't love it, or you have some reservations about certain minor aspects of the matter.
Which is fair enough. But I'd prefer people to say "I generally agree" which would be FAR more accurate.
[LoR mutters to himself] "Come on England... Come ON England..." Unintelligible sounds "Not again.... Please, god.... Not again...."
That would explain why I didn't get it. I sort of feel the same way that @Killer Angel does on this one.
You know me, each to his own. I'm never going to lash out abrasively because someone likes something different to me or thinks a different way. We're all individuals so fair enough. The only exception would be if it were actively damaging people or destructive. Yes, probably lots of people would want to pick apart that last sentence. It is definitely situational and specific and based on all of the information I had.
We are in agreement on one point. I can't tell whether or not you've ceded my original point, as you continue to make arguments which support the point we agree on. You said that two negatives in a sentence revert to a positive. I said that they do not, though they are stylistically and (usually) grammatically incorrect. You have provided many examples to support my notion that they are inelegant at the least and incorrect at the most in formal writing, supporting my point (and yours?). You have provided no supporting evidence that two negatives make a positive in spoken or written English. If I say "I don't go no mashed potatoes," it does not mean that mashed potatoes magically appear on my plate, and there is no rule in any style guide, dictionary, or other source that say they do. Again, language is not algebra. Double negatives do not resolve to a positive and you have provided no evidence from any source that states that they do.
Simply put, English doesn't support a negative discord, and thus double negatives grammatically turn positive (or at least the inverse of the single negative). However, it's such a common "mistake", especially in various American dialects, that it's generally clear what's meant and thus accepted in quite a lot of situations, even if it is technically wrong. In the case of your potatoes, that sentences grammatically implies you got potatoes, even if any American will understand that you really mean you got none. If you want an example of a negative discord actually being grammatically correct within a language you should look at French. Old English (and Dutch, and German) used to work like that too, but it's mostly disappeared, as evident by the scientific literature you can find on the subject. You can still see it in Afrikaans though. Here's another example of a scientific text explaining modern English doesn't allow negative concords, even if the negative concord was actually the rule in older forms of English (and other germanic languages). And that if you use two or more negative meanings in modern English they now logically cancel eachother out thus resulting in the inverse of the negative, which generally speaking will be a positive. Natural language actually works quite well from an algebraic point of view. The issue is that language constantly evolves and if enough people make a "mistake" eventually that becomes the new normal. Which makes it difficult to keep the rules consistent for any period of time. Different groups of people will develop their own dialects/slang and happily use that no matter how much teachers might complain their grammar is wrong. Plus natural language is ultimatly only something we use to communicate, not to prove things. So even if you make "mistakes" it doesn't matter much, as long as it still succeeds in communicating the message. Ultimatly the formal rules are only there to aid communication, but humans are more than capable of dealing with "mistakes". Which is why you constantly see all sorts of grammatically incorrect nonsense or made up words in literature, poetry, music etc. Some of which eventually makes its way back to the formal language (e.g. shakespeare inventing 1700 words). Also this is ultimatly the only thing that really matters to determine if something is grammatically accepted in a formal setting. It being accepted in an informal setting doesn't matter because no-one really cares about grammar in an informal setting, they only care about being understood. People are willing to accept pretty much anything in an informal setting as long as it gets the job done.
You have provided no evidence that double negatives resolve to or even imply a positive in English. You said that they do. You've gone to a great deal of trouble to show they they are frowned upon, that they are considered grammatically incorrect in formal English, and that they are generally poor diction. With which I have repeatedly agreed. My problem isn't with usage or diction. What you said, though, was that double negatives resolve to positives in English. They do not, in any idiom, even in formal idioms (where, yes, they are technically "mistakes").
According to the last scientific text I linked a negative concord is defined as followed: The use of a double negative (or multiple negatives) where the negatives do not cancel out. It also states a negative concord is not allowed in modern English this means that in modern English double negatives do cancel each other out. According to you; If two negatives cancel out what can they make other than the corresponding inverse of the negative, in other words the corresponding positive?