A must-read! Grammar, world Englishes and LC

I was looking for something that explored the debate as to whether punctuation is a grammar issue or not and I found this. I disagree, incidentally, as I think that punctuation and syntax are both grammar, but this post by an American English teacher explores and exemplifies a range of grammar and punctuation ideas and brings in American English and language change... so read and take notes but you don't have to agree!