coin

a coin on the floor
Once I had a very funny student. One day, I wanted to introduce him to what to say when you find something on the street that someone dropped. So before the lesson, I put a coin on the floor under the table, so that I could draw his attention and reproduce the scene in the lesson. At the very moment when I just pointed to the coin, the student put his foot on it, took the coin immediately, put it into his pocket and grinned at me. I not only missed the chance to show him the sentence pattern, but also I was taken aback and didn't know what to say!