I am sure this has happened to other teachers, but the sheer disrespect is what convinced me to post this dialog here:
Student: “Mister Karabekian, what the difference between ‘through’ and ‘thru’?
Me: “Nothing, ‘t-h-r-u’ is just an abbreviation of ‘t-h-r-o-u-g-h’.”
Student: “Nah, that ain’t right, you don’t know nothing about English and you an English teacher? Thru be on all them drive thrus and stuff, I ain’t never seen no McDonald’s with a ‘Drive Through'”
Me: “That’s because it works as an abbreviation, and because some people might get confused when they find themselves unable to read the word ‘through'”
I’m not sure she should have been discussing who “knows about English”, but I dealt with that privately after class.