Tagging "bad" grammar

In last Friday's Milwaukee Journal Sentinel, staff columnist Jim Stingl ran a piece on a local English teacher's reaction to a grafitto in her neighborhood that read as follows:

Where da bitches at?

Here's the text of the teacher's corrective:

Hey, Tagger!

We’d like you to work on your grammar, please!

Your tag SHOULD read as follows: Where are the female dogs?

1. The use of the verb are allows you to write a COMPLETE SENTENCE. (Without it, you have a fragment, of course – missing the predicate of the sentence. The subject is dogs.)

2. Proper spelling of the article the is NOT da.

3. Slang is not appropriate, even in most casual writings (unless, of course, it’s being used as part of dialogue, but even this particular use wouldn’t be appropriate for a general audience such as the passers-by who are subjected to your work.)

4. The use of at is not included here, as the word itself is a preposition, which shouldn’t be used at the end of a statement.

I don't usually fret too much about prescriptivism, and I have a feeling that by engaging this reaction in the present forum I'm basically preaching to the choir, but here goes ...

The tag was written in a variety of English known to linguists as African-American Vernacular English (AAVE). Distinct from standard American English, AAVE shares a number of features with English-based creole languages, as well as regional dialects of English spoken in the British Isles, North America, and the Caribbean.

Re: point 1 – The absence of a copula verb (form of be) in the tag is normal in AAVE declarative sentences. This structural pattern is found in many of the world's languages, including Russian and Hebrew, and does not indicate lack of "completeness" in a sentence. One could just as easily argue such a zero-copula sentence is communicatively economical, since there is no ambiguity as to what the grammatical subject is.

Re: point 2 – Dental fricatives (represented in standard English spelling by "th") are not found in most of the world's languages, including AAVE. The spelling of [da] accurately reflects the phonetic shape of this word.

Re: point 3 – If "slang" is not appropriate in most non-quotations, then the anonymous tagger finds him/herself in good literary company, that is, with the likes of Chaucer, Shakespeare, Dickens, Twain, and Faulkner. One should also mention that bitch and female dog are not synonymous here. A glance into the Oxford English Dictionary is illuminating. Definition 2.a for the noun bitch reads as follows "Applied opprobriously to a woman; strictly, a lewd or sensual woman. Not now in decent use; but formerly common in literature." Here, the tagger is following in the footsteps of writers such as Shakespeare, Kipling, and D. H. Lawrence.

Re: point 4 – Preposition stranding is not only entirely normal in all registers of written and spoken English (consult any current major manual of style, such as CMS), it is in fact unavoidable in many cases, e.g.: That surface is not to be written on. Again, AAVE grammar is line with that of dozens of other languages.

Image above from here.