What are standard references for English language?
I always wonder whether to refer (in stating rules) GM or other English language websites for grammatical rules. Furthermore, I used to get tips and explanations from you as well. Will this be enough to convince someone who claims him as grammar-savvy?
Well, there are many websites like GM dispensing good solid grammar advice. Of course, it would be impossible for them to deal with every point of grammar, or deal with the rules of advanced grammar - it would take a massive amount of data to do that. One of the problems that arise is that of terminology. The terms used in more advanced grammar often differ from those in basic grammar, and this does cause some confusion.
Generally, though, I think you'll be okay with what you're doing now.
PaulM
ps: If you want to buy a textbook (one I use) that deals with slightly more advanced grammar, let me know and I'll give you the details.