I have recently noticed something that really bothers me. It bothers me only because I cannot believe I’ve never noticed it before!
I keep seeing people commenting on websites and using the term “on accident” instead of “by accident”, which I was taught to use. I didn’t even know “on accident” was a thing!
I went and did a bit of hunting around to find out if I’ve been wrong all my life and found this: http://grammar.quickanddirtytips.com/on-accident-versus-by-accident.aspx. I’d consider it worth a read – I’m actually a little embarrassed I didn’t go there first, I love Grammar Girl!