It’s not illiteracy, they can read, they can write, they just don’t put the words in the order a 100 year old book says they should. Which is your problem, not theirs.
The question you should be asking yourself is, "Who can be understood by more people? The one who speaks slang or the one who speaks correct grammar?"
An illiterate who invents speaking conventions can understand what I am saying, but the converse is not true.
You posted: It’s not illiteracy, they can read, they can write, they just don’t put the words in the order a 100 year old book says they should. Which is your problem, not theirs.
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I disagree. The grammatical errors demonstrated in this thread result in imprecise speaking and writing. True, grammar books are old, but that only shows that the rules are long-standing. The misuse of language is unattractive and suggests a lack of care in what one is saying. Sadly, most don’t even know that they are making errors, much less how to correct them.