<> Why no article before cours?

Hi White, 

The expression is -

‘Avoir cours’ which means to have lessons/lectures , to have school. That is just how it is, you will French students saying for instance-

“Je ne peux pas venir, j’ai cours ce matin”, meaning they have to go to school.

But they might be more specific and say -

J’ai un cours de français demain.

Hope this helps!