Feedback: showing the result of the pressed key
To help the player out while typing, there is a very friendly feature which is active by default: showing which key was pressed (if not the correct one). If the correct key is pressed, then the character will turn into the correct color.
The player immediately sees something is off once it does not turn correct and you as the educator (if present at the same location) can interpret what kind of visual recognition mistake the player is making.
If you want to increase the difficulty a bit, you can hide the pressed key in the little bottom right square via the disabling of the Premium > Show pressed key option.