Did you ever stop reading suddenly and return to reread a sentence, possibly more than once, and consider how it was written and whether it even made sense?
I do this all the time. Just this morning while reading Anne Perry, one of the posh characters responded to Inspector Pitt:
I'm sorry you have taken the trouble to return, since I'm quite sure I can tell you nothing more.
Is this little piece of dialogue grammatically correct? Is it logically correct? Since this sentence is a part of the dialogue spoken by Charlotte Ellison, it, arguably, could be purposely incorrect in order to display the character’s less-than-perfect speech or it could be acceptable every-day grammar that we see or hear without stopping to consider what it really means.
My question is: how do you tell someone nothing more?
I can’t think of anything more to say so I’ll just leave the question for individual contemplation.

He could say instead, “… I have no more to say.” Or could he? Could he say, “… I cannot say anything more.” ?
LikeLike
I suspect that the idea of saying nothing is a common locution even if it is illogical or even impossible. If you reread my final sentence you might find some agreement with your second alternative. I would conclude that the negation is misplaced in the original sentence and could easily have been rephrased to eliminate the illogic.
Interestingly, this is only one example of “Don’t Say Nothing” from the novel so I suspect it is an accepted convention, at least in England.
And please understand that I am no great grammarian myself. Maybe I should look it up … but where: Fowler, Fawcett, Fiske, Strunk?
LikeLiked by 1 person
Re the accepted convention – you are right; I’ve read a lot of British lit and have come across it many times.
LikeLike