The grammaticality of “that don't impress me much”
In Gadsby, which is almost grammatically not wrong at all, occurs just a solitary construction that I thought was awkward. It is said that "... folks today who claim that 'a child don't know anything.'" "No child knows anything" could own its position, as it is grammatically right, and contains not that symbol that Gadsby's author is trying to avoid.
Could I obtain a justification for this display of grammatical inaccuracy? Is it a willful play on grammar?
For additional information, Gadsby is a lipogram, by Mr. Wright. You can flip through it at this link.