I am going to explain to you what a teacher does everyday.
Everyday a teacher smells shoes, those shoes are very stinky. When they smell very stinky shoes they get a cold and cough alot. When they are better they do it again and again and again.
Everyday they also make spells because they are witches. They make potions like harming potions or poison potions and they secretly splash them on people. Sometimes they even splash it on chocolate and when kids eat it they get sick after that day.
So you can see that the things a teacher does all day are practicing spells and smelling shoes, so I really think a teacher is a witch.