"A child don't know anything" in Gadsby — grammatically right? [duplicate]

Possible Duplicate:
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.

Solution 1:

As Peter Trudgill has said,

Standard English fails to distinguish between the forms of the auxiliary forms of the verb do and its main verb forms . . . many other dialects distinguish between auxiliary I do, he do and main verb I does, he does or similar . . .

In this example, don’t functions as an auxiliary verb, and can be seen as representing non-standard speech, as well as avoiding the letter e. The writer could have made it even more typically non-standard with a child don't know nothing.