Not a grammar Nazi but I host lots of volunteers and I have grown to hate, hate, hate the word 'like'. (Most are 18-25, female and British/European/American).
"I was, like, going to, like, my friend's and she was, like, late so, like, I was really, like, cross with her." Arrrrgggghhhhh!!!
I've started, like, really calling them out, like, on using the L word or am I going to stunt their emotional growth, like?!?