Well, without even reading this thread. I know full well that I will have been guilty of most of them.

I still don't know what to do with a semi-colon. It's like one of those gifts you are given by a well meaning relative, but never know what to do with, so it gets left redundant in the spare room...

I suffer from greengrocer's apostrophe, even though I have no excuse. I know what an apostrophe is for but I still place them inaproppriately without thinking, as a consequence of rattled off pieces of writing - especiallly on the interenet!

Aggh! And the one that's really bugging me right now, isn't grammatical. But spelling based. My spelling is poor in general, but in particular I never know where the double consonants come in words like:
reccomend/recommend. And of course now I can't think of any other examples, but they seem to cause me confusion every time I post to Mudcat.

Now on the one hand, I have a love of the English language, which could make me inclined to learn to correct these errors.. Of course within an academic context I would correct as appropriate. Because in my mind, that context renders such details, highly important.

And yet I also have a dislike of literary smugness, where a person is corrected for superficial errors in writing and punctuation rather than the otherwise clear content and meaning of their posting - in casual conversational contexts such as interner fora.

So I prefer to rattle off my posts on here - without spellchekcig, knowing quite full well, as I do, that they will annoy, infuriate or otherwise attract the pompous disdain of the most pedanticaly anally retentive members immensely. Just one very mild expression (and amused) of my anarchic disdain for ANY form of empty and inflated self-asserted "authority".