Ooooh! Wanton use of the apostrophe gets under my skin eve'ry time!!!

The use of "or" as an equivalent. "Or" inside parentheses with acronyms. "Or" used to finish an inclusive list. All very wrong especially in science texts. These are not allowed in legal docs.

"6 kilometers, or 3.7 miles." Not an "or." They are the SAME!

The Best Place On Earth (or TBPOE). No "or" needed.

"This medicine can cause heart attack or stroke." Oh! I get a choice? Really?

1st one is THERE IS NO FUCKING "T" IN ACROSS...and if I hear "NUCULAR" one more time ...I'M GOING TO GO "NUCLEAR"...oh...and let us not forget "IRREGARDLESS"...it is "REGARDLESS" YOU DUMB ASS MOTHERFUCKING TWATWAFFLES !

Not a grammar bit completely:: I hate people speaking/writing in the second-person-universal about oneself. And just in general.

I think this comes from teaching children to write as if they are talking/writing a letter to a friend.

"When you are president parent you must ask yourself,..." Idiotic.

One instruction manual had 7% of the words as "you," its variants, and all the extra words needed to support the use of "you." The book could have had nearly 30 fewer pages.

Once you get started it is impossible to not used "you" again. often in the same sentence.

One of my responses:

"""And then, when you are finished working with your music program on your computer in your studio, you should use your index finger on your hand to click your mouse button to hi-lite your clip in your song displayed on your monitor.

And then use your ring finger (or your middle finger) on your hand to click your right button on your mouse to display your context menu so you can choose from your choices to change your clip in the way you want to,...

And then when you are happy that you did what you wanted to process your clip in your song, click FILE on your menu in your program to save your project to your folder on your hard-drive
"""

Misuse of "then" and "than" can definitely trigger me...

I generally don’t care except for my boys using text slang. As long as I understand the thought that the person is trying to convey. I’m not perfect nor pretend to be.

Mine is the rise of "less' and decline of "fewer". Drives me crazy. Fewer is a number and less is an amount but now so many people, even those educated ones just use less.

Two things that annoy me slightly are:
Use of adjectives in place of adverbs, eg he runs 'fast'.
Modern use of 'alternate' in place of 'alternative'.

None, let go of the small things in life

Please don't axe me a question unless I can hachet you the answer.
Me and Pete went to the store. No! Pete and I went to the store. Or Pete went to the store with me.

Official communication from a company, the press, a website, a government agency, and any other organization.

It's usually autocorrect that screws me up. Sometimes I just leave words out completely. Like "I'm buying your bullshit." I left out the NOT. Did that one today.

When someone didn't hear and asks, "What happened?" I reply, "Nothing happened."

Everything trump says. Whatta moron

No one is perfect, grammatically or otherwise. Mistakes are bound to be made. What triggers me aren't the mistakes but rather those who are content with mediocrity. In radio, we called it 'lazy mouth'... Things like pronouncing "picture" as "pitcher", and midwestern-isms like "farty", "fark", "harse" for "forty", "fork", and "horse", respectively.

To Too
Their There
You're Your
This is simple laziness.
That's about all I let bother me. Grammar is more about the area where you live. Things like "y'all" don't bother me because it's in the vernacular. The same applies to things like "I seen that" in certain places. I understand how this bothers people but it doesn't get to me.