A Way to Get Students to Speak English

This morning, I told Class 209 that I would teach them a song after we finished Lesson One today, if the points the whole class got were over 50.  Though still, they didn't reach 50 finally since I didn't ask as many questions as I did the previous days, they tried their best.  Tomorrow, they can sing the song, I believe, because I'm going to pose many questions.  I love to hear students speak English in and out of class!