Other tricky foreign stuff:
It’s per se, not per say.
Chaise longue. Not “lounge”.
Au gratin is two words.
See, this is why I think we should drop the generic designation of ‘Cavalry’ and go to the 17-19th century traditions of type of cavalry: Hussars, Dragoons, Cuirassiers, Lancers, Hobilars, etc.
The opportunities for misspellings and mix ups would be endless
+1
And yet, I do.
sneers at even sven
Or because they model their spelling after other illiterate idiots, and the incorrect versions spread like wildfire (c.f “definately” <sic>). 
Don’t even get me started on Brett Favre and Ben Oglivie.
[Edit: Curse you BubbaDog!]
Cas, the way we might dress when we go to “din-din” (sic)* with my mother-in-law. “Shall we go out to din-din? Are we going cas?”
She is 71.
*Or sick, as it might be.
Queue: What British people stand in, or where your orders are pending.
Cue: An indication for a specific action.
Que: Nothing. It’s not a real word. Stop writing it, dipshits!
Burro: Ass
Burrow: Hole in the ground
Please learn the difference. Thank you.
Robin
¿Que?
I know, it’s not English, it doesn’t count.
The difference between Calvary and cavalry clearly explicated: here
Antiques Roadshow US had a militaria expert who pronounced it “calvary.” IIRC, they fired him when he had a buddy bring in something from his shop for him to shill. I thought they shoulda fired him for not being the expert he claimed to be, based on his mispronounciation.
Lead: a heavy metal; you make soldiers of it
Led: past tense of a verb
Typical spellcheck mistake that has proliferated.
You know, for the longest time I thought it was spelled (and pronounced) “calvalry” (referring to mounted infantry).
Suck on that.
Oh, thank you. This is the one I see the most. I cannot get the difference into their fool heads. But then again, the people I work with say things like “breasteses.” What kind of freak are you? Is that more than two?
Axe: an implement used for chopping wood.
Ask: to inquire.
Don’t axe me a question. Not now, not ever.
If he was a Lapp, perhaps there could have been a reined reigning reindeer in the rain.
I don’t have any idea if this will help anyone but me, but I used to use the mnemonic device of remembering a knight was a “cavalier.”
Well, that’s just stupid. The incorrect spelling makes 100% sense.
Ignorance fought. Although, I had to go look this up for myself, and Wikipedia says that
If only you had had the foresight to cite a site (or even four sites)!
Unless it’s used as the material to build a large blimp.
Ensure: to make certain.
Insure: to underwrite.
I see this one a lot (not alot).