Well for me, I’m from the Southern US, the Carolinas. We (Blacks/African-Americans) have an entirely different language, or rather a combination of languages in a Southern dialect that is not English. I can speak Gullah Geechee (at home people just call it Geechee), we also speak an entirely different language, African American English (someone decided to label Ebonics). This doesn’t include all of the other slangs, and hip-hop speech that’s become apart of our culture to describe things we don’t want White people or “the man” listening to. You only know these things if you spend time in our communities and spend ample time around Black people.
While many Black homes don’t use anything but American English, we all have family members who speak any of these other languages depending on what era we were born in, what part of the world our descendants originated, our geographic location in the country, and or national origin.
Here in Florida, Black Haitians speak a different type of Creole from Blacks in New Orleans African-Americans. We have a lot of different languages. Black in America isn’t a monolith. I think an issue is that because Whites have been the majority for so long, people of color were forced to speak English in order to participate in society. We did so without forsaking our native languages/local tongues.
All this in addition to speaking good old “American English.