I don't even know. I'm just a speech therapist, I wasn't even taught about how to teach reading and most language skills. 90% of my job is teaching 5th and 6th graders how to form grammatically correct sentences.

Part of it is totally cultural and therefore completely acceptable. We have to know the difference between a language difference and a language disorder and it's actually illegal to "fix" a cultural language difference. The other part is lack of parent education, most of these parents barely have a high school education and more than half my schools parents are non English speaking which is harder for those special ed kiddos who already have a learning or language disorder.