GrandDaughter1 had a phone for Christmas and sometimes we chat on Whatsapp. I use my computer for this so if I'm not at my desk she sometimes has to wait for a reply.
If she suspects that I'm there and just ignoring her - as if! - then she will deliberately write something like this: You should of seen me.
She knows I will be incapable of ignoring it and will have to reply in order to correct her grammar.
Now isn't that mean to take advantage of Grammar Granny?P.S. I'm not actually that ardent a grammarian; there are just some things I can't abide.