So I'm a linguistic descriptivist, which basically means that I think the most important part of communication is... actually communicating. Shocking, I know. Basically, if you have something worth saying and you manage to get your point across, I don't really care if you split infinitives, or scatter participles, or fail to conjugate properly.*
...but you know what the second most important part of communication, or rather, writing is? Not sounding like an utter dumbass.
...and the best way to not sound like an utter dumbass? Don't use words when you don't have any friggin' idea of what they mean.
E.g. if you don't know how to use "whom" properly, then don't ****ing use it. If you don't know what "e.g." means: then don't ****ing use it.** If you don't know the difference between "eloquent" and "elocution:" don't ****ing use them. If you can't figure out how to use Elizabethan, Middle, or Victorian English properly, then, please -- for the love of god or some other ontologically valid being who may or may not be a purple spaghetti monster dressed in suspenders, I'm begging you -- don't ever use them. If you don't know how to use a semi-colon: learn how.
Essentially: I would much rather someone speak and/or write their own dialect/register of English fluently than speak Standard Written English like a second language learner. Because, you know what? Second language learners have an excuse. We don't.
(This comic found on the excellent Language Log, because, while I'm crazy, I'm not crazy enough to write my own comic, or to root around and risk getting stranded in my bog of a hard-drive for a picture of Archibald the Asparagus.)
*Don't get me wrong. I would really, really, really like it if people would stop writing "you're" when they mean "your," "it's" instead of "its," and mixing up "discreet" and "discrete." (That's like, 80% of my freelance livelihood right there by the way. Righting/re-writing people's homophones and shifting their apostrophes.) I'd also like them to learn how use the subjunctive, and how to construct the past and present perfect tenses properly. But I can realize that it's not that important in the grand scheme of things. And people do make mistakes. I get that. It's cool. I would much rather than people have imperfectly 'formatted' thoughts that are worth hearing/reading, than read/hear grammatically correct trivialities. But it looks like I'm not going to get that either. So I take my daily dose of Fukitol and start half my sentences with conjunctions in a passive aggressive bid to frustrate humanity out of its stupidity. (No results yet.)
**It means: exempli gratia, 'for the sake of an example,' so, really, you could just say something boring and English and simple like "for example:", 'i.e.,' on the other hand, means 'id est' (that is) which usually introduces some sort of clarification or definition. But again, you could just use the boring old English "that is" and never have to think about it again.
Also, as you've probably gathered from the preceding paragraphs, I could totally do without anyone ever trying to write period English. Ever. Again. There is no profanity in any language I know to express my feelings on the subject. Stop, people. Just stop, okay? I can barely tolerate the Quaker 'thee' in the old Star Trek, and I'm told they're using it correctly.
But it looks like that probably won't happen either. So... que sera sera.
Oh, yeah, and another thing: for god's sake, look up the definition and spelling for foreign phrases; make sure it actually means what you think it means. Google is literally at your fingertips. Even if you've got the wrong spelling, the right one will come up; this is one of the few moments in life where other people's incompetence/ignorance will actually work for you.
And proof read. Do as I say, not as I do.