Some that annoy me at work:
When using the phonetic alphabet, using Sugar instead of Sierra, or Mother instead of Mike. Or when they say "A for Alpha" or "A as in Alpha", just fucking say "Alpha".
Confusing "UNsecure" with "INsecure". If we've had to force entry somewhere, the property is now "UNsecure", not "INsecure". The building isn't suddenly paranoid about its weight.
Usual office/management speak. "Touch base", using "Action" as a verb, "Low hanging fruit", "Sing from the same hymn sheet" etc.
And in general:
People who use "parse" or "unpack", "Break the internet", any programming language used in normal discourse like =! or =/= instead of ".. Doesn't mean..".
When people don't know the difference between "Bought" and "Brought", "Every day" and "Everyday", and "Apart" and "A part". Especially the last one because "Apart" and "A part" have opposite meanings.
Someone using "You must be fun at parties" or the "No fun allowed" pic when they've been corrected on a minor point.
People, usually pretentious reviewers, using the word "Important" when describing music or a film. "The most important album of 2019".. fuck off, it's disposable pop trash that will be forgotten in less than 12 months.