Let's speak English.
Let's change to English.
Now, it's English-only time.
let's move on.
If you know the class is capable of using English, or
if you are conducting CLIL classes, you may have to remind them:
In English, please.
Try to use English.
Say it in English,could you?
Use English as much as you can.
.....Natcha 3EN 023....