critical analysis of correct and incorrect grammar
Are you asking about the relationship between grammar usage and socio-economic class of the speaker? Are you analyzing the use of non-standard English? Are you looking for some other type of analysis that I can't infer correctly from your extremely limited question?
If you are analyzing grammar as related to economic or educational influences upon the speaker, you could support the proposition that training in the rules of usage for grammatically-correct standard English is related to the amount and type of education received.
If you are arguing that usage in dialects such as African American Vernacular English is "incorrect" grammar, I think you are missing the point. AAVE, in a grammatical sense, is a separate language from standard English, with its own set of guidelines structuring how words are properly used to communicate. AAVE is different than standard English - it has nothing to do with "correct" or "incorrect."