What irritates you the most with your own language?
Mine is people who separate words when they write. I'm Norwegian, and we can string together words indefinetly to make a new word. The never ending word may not make any sense, but it is gramatically correct
Still, people write words the wrong way by separating them.
Examples:
"Ananas ringer" means "the pineapple is calling" when written the wrong way. The correct way is "ananasringer" and it means "pineapple rings" (from a tin).
"Prinsesse pult i vinkel" means "a princess fucked at an angle". The correct way to write it is "prinsessepult i vinkel", and it means "an angeled princess desk" (a desk for children, obviously)
"Koke bøker" means "to cook books". The correct way is "kokebøker" and means "cookbooks"
I can't speak for all native English speakers, but in my experience we're very accepting of imperfect grammar from non-native speakers because we know how crazy this language is.
It can be pretty confounding, the words that look the same but are pronounced differently. Through, though, thorough, tough, trough.
There are no rules, you just have to learn it. And it could be confusing if you mix them up. Through and throw, for example.
English has never had a spelling reform, but you can see the "real" spelling in informal language sometimes. Through = thru (in texts and chats). Tough = tuff (in slang and brand names).