Why Study Grammar?

How can teachers walk the line between boring, isolated grammar instruction and no grammar instruction at all when teaching a variety of students?

I'm a believer in the idea that you have to know the rules first, and know them well, before you break them. I think this ESPECIALLY applies to grammar -- it is hard to take someone seriously if they are speaking improperly. I wouldn't take a grammar lesson from someone who told me "you gots to learn grammar or else you're not gonna be no good". That's not to say that this dialect doesn't have a place, or that it is not 100% effective for those who understand it and use it, but it's not standard English ... it's not proper grammar.

I think that in order to communicate with people we need to have some kind of common ground. Yes, people can speak their different dialects to varying discourse communities, but it would be nice to be able to walk up to a stranger and communicate with them without having to analyze their dialect first. I'm not advocating that we all speak the King's English or anything, I just think that we need to be able to have a baseline dialect for communication. In that vein, I really like Calderonello's idea that we should teach grammar in context -- not get bogged down with the nitty gritty rules and terminology, but teach children how to USE grammar effectively in everyday life.

Easier said than done, though. How can we take a class of various language-speakers and even more varying dialects and teach them all that baseline? An even harder question is: how can we make that fun?! I think the difficulty of these questions is why teachers often resort to language drills and standard-English, isolated grammar instruction. It is HARD to toe the line between improper grammar and 'good enough' grammar, especially when you have to take lots of student dialects into consideration. Is the best way to do this to simply correct grammar on papers and assignments and hope that it sinks in? Or are some sort of specific grammar exercises necessary? Where do we stand between the King's English and the chaos of millions of dialects? Where SHOULD we stand?