The author drew a distinction between making a grammatical mistakes, and a vernacular dialect. He didn't claim that there were some vernacular dialects that embodied mistakes and others that didn't. I can't imagine any linguist who would.
Fair enough. When you said "vernacular variants" (as opposed to dialects) it sounded as if you were including all vernacular variants including simple grammatical mistakes, sporadic use of slang, etc.
What I'm saying is that all vernaculars have consistently observed (surely you don't literally mean well-specified) grammatical rules.
I agree that all vernacular dialects have consistent rules. And you're right, I did mean consistently observed, not well-specified.
The author drew a distinction between making a grammatical mistakes, and a vernacular dialect. He didn't claim that there were some vernacular dialects that embodied mistakes and others that didn't. I can't imagine any linguist who would.
Fair enough. When you said "vernacular variants" (as opposed to dialects) it sounded as if you were including all vernacular variants including simple grammatical mistakes, sporadic use of slang, etc.
What I'm saying is that all vernaculars have consistently observed (surely you don't literally mean well-specified) grammatical rules.
I agree that all vernacular dialects have consistent rules. And you're right, I did mean consistently observed, not well-specified.