[Denis DNT]

It's embarrassing when our own rules screw us.
Last year I had a rule in my class of Korean students not to speak any Korean during English lessons. The penalty was a yellow card; twice = two yellow cards = a red just like in soccer. Two months later they gave me a red card when I couldn't get them to understand a sentence and said it in Korean. It's a lot of fun to them to see the teacher caught in the rules and embarrassment to us.