[puzzledobserver]

I am not a linguist, but I don't think that many linguists would agree with your assessment that dialects, leet speak, short form writing, slang, creoles, or vernaculars are necessarily ungrammatical.

From what I understand, the modern understanding is that these point to the failure of grammar as a prescriptive exercise ("This is how thou shalt speak"). Human speech is too complex for simple grammar rules to fully capture its variety. Strict grammar and lexical rules were always fantasies of the grammar teacher anyway.

See, for example, the following article on double negatives and African American Vernacular English: https://daily.jstor.org/black-english-matters/.

[mcswell]

I am a linguist, and I agree. But it does complicate the grammar to allow for these other options. (I haven't studied leet speak, but my impression is that it's more a matter of vocabulary than grammar, and vocabulary is relatively easy to add.)

For the record, the parser I worked on ended up having the "interesting" rules removed, leaving it as a tool for finding sentences that didn't conform to a Basic English grammar with a controlled vocabulary--and used to QC aircraft repair manuals, which need to be read by non-native English speakers.

[throwaway11460]

There are languages that have fully codified grammar which completely covers everything people actually use (and more). But we spend 10 years learning the grammar itself 1-2 hours every day at school (then you have literature etc on top of that)...

I see it as a complete waste of my youth, BTW. Today I speak English that I learned through listening, reading and watching, and all of this mother tongue grammar nonsense that used to stress me out daily at school and during homework is absolutely useless to me.