Khadaji, I don’t want to bother coming up with links because, as a former student of linguistics, trying to explain to people that “no, the black people aren’t talking wrong” makes me a little peeved. Black English is every bit as valid as every other variety of English. You could probably get a good start by googling “African American Vernacular English” or “Black Vernacular English” - AAVE (and less often, BVE) being the most common terms for it to my knowledge. (Shalmanese is sorta wrong, though - no linguist would have been surprised at this. If AAVE hadn’t had a consistent grammar and syntax, it would have been the only dialect in the world that didn’t. And this was very, very common knowledge, at least among academics, long before Stephen Pinker.)
AAVE is just a distinct variety of English, spoken by Black Americans population. Irish people also speak a dialect of English with words and pronunciations that are sometimes unfamiliar to the rest of us, and even grammatical constructions that are unique to Irish English. Every language has dialects. There’s a lot of vague ideas linking particular grammatical features of AAVE (the habitual be, the dropping of copulatives, various aspects of its sound system) to West African languages, but I don’t think there’s enough historical data for that to ever be anything but pure speculation.
But yes, the unique features of its grammar are consistent - for example, the aforementioned habitual be. “Be” is used to replace “is” in some sentences if it’s describing a habitual or repeated action. I can’t dig up a cite right now, but I’ve read about a study. Two groups of kindergarten-age students, one group white and one black, were shown pictures of characters from Sesame Street. One depicted Elmo (an obnoxious red puppet, for those unfamiliar with the show) eating cookies, and the other was a simple portrait of Cookie Monster (who, on the show, eats cookies constantly.) When asked “Who is eating cookies?” both groups of children answered that Elmo was. When asked “Who be eating cookies?” the white children again replied that it was Elmo, while the black children replied that it was Cookie Monster, since he habitually eats cookies.
So AAVE clearly expresses a grammatical distinction that is missing in Standard English - in this one particular area, it’s actually more sophisticated. (In the end, of course, all real languages are capable of expressing any thought; you can’t really describe one language as generally “primitive” and one language as generally “sophisticated”.)
There is also research that discusses when exactly “is” may be dropped from a sentence. The rules are pretty complex, but when I read them, they seemed to describe usage pretty accurately according to my own experience.
You’re falling into a common trap of assuming that one dialect of a language is “correct” and the others are somehow deficient. But every language has dialects that have unique sounds and grammar - for instance, the Spanish spoken in Latin America lacks the “th” sound that the Spanish of Spain has, and instead merges it with the “s” sound. From the outside, I don’t think any English speaker would dream of considering one group wrong, but we internalize what we’re taught in Elementary School to the point that we believe that people who talk a certain way are simply talking wrong, dammit!
Which, of course they’re not. But we think that speaking a certain way signifies a lack of education, or simply being to “lazy” to speak correctly, because we’re taught from when we’re young that “ain’t is not a word!” and elementary school teachers rap our knuckles for not pronouncing both Rs in “February”. The standard dialect of any language is really just the one spoken by the historically wealthier class, because it naturally becomes the dialect used in education, and the lower classes often gain advantage if they learn to speak it.
It’s interesting, though, how many black people are conversant in both AAVE and Standard English, to the point where they instantly switch between them depending on who they’re talking to. I had a boss once who sounded pretty damn white when he spoke to white customers, but could turn around and sound completely different talking to a black customer. I’m sure most black people in the US are fluent in both, which is an interesting thing to ponder for any monolingual white people out there.
(If you really are surprised at the idea of Black English being a real, full-fledged dialect with its own rules, though, you ought to start learning more. There’s not exactly a shortage of authors who have written in it - Toni Morrison springs immediately to mind, even if most of her writing is in a historical form of the dialect. And you can pretty easily find music in AAVE. Around here, during the middle of the night, when I’m trying to sleep, it’s extremely easy to find such music.)