Why do so many people have a problem confusing loosing with losing.
I have no idea, but it’s one of my biggest pet peeves. Not that it’s a great excuse anyway, but they aren’t even pronounced the same, like two of my other peeves: peak/peek and heel/heal.
The only thing I can figure is that the growing epidemic of non-readers are dragging us all down. Hearing language vs. seeing.
Agreed. Please let me add “affect” and “effect.” Jeebus.
Peak/peek/pique.
Fixed that for you. (shudder)
The people who confuse peak and peek are rarely the people who even realize pique is a word, in my experience.
That theory peaked my interest a bit.
I think my biggest peeve is people who keep peeves as pets … get a cat or something will ya?
Not as infuriating as “it’s” as a possessive.
m’y
you’r
hi’s/he’r/it’s
ou’r
you’r
thei’r
advice/advise
I know the difference between lose and loose, but forget which is witch sometimes.
Stationery stores that change locations …
Principle school administrators that can’t spelt …
That one’s a little more challenging because each one has a noun form and a verb form.
Noun:
A special effect is something we might see in a movie like Star Trek, whereas a special affect might be how police describe my overall demeanor after a traumatic event.
Verb:
Trump thinks the media is conspiring to unfairly affect voters; he has accused them of working to effect a Clinton victory.
Meanwhile, I’ll add the brakes/breaks confusion some people struggle with.
Irregardless, lieing about witch word is rite is worser. 
The correct word is “wurst”.
I never sausage a nitpick before!
How about phased instead of fazed?
In informal settings such as this I chalk it up to fast typing and lack of proofing. In formal writing, lazy editing. With the former, I give the writer the benefit of the doubt – they likely know the difference but they slipped up. With the latter, there’s really no excuse.
I get letters from my son’s English teacher that confuse you’re and your.
People who make a thread title in all lowercase. It’s not necessary to capitalize every word, but at least capitalize the initial letter of the first word.
WAG: Because it’s far more common in English to spell the “oo” sound with a double o than with a single o.
Why do so many people end a question with a period instead of a question mark? 
Not related, but, people who add apostrophes to words that end in ‘s’ like get’s or eat’s.