WHY "double French " and what does it mean?

Question

This is so frustrating while reading, knowing very word but not the meaning. Why double French ? My guess is "they once had French course" based on a fact from the novel. But why double it??? Does it mean "they fail the French test and take the second test?"

here is the sentence :

One of the boys I knew at school had taken a round-the-world trip and come back somehow removed and unknowable, like he wasn’t the same scuffed eleven-year-old who used to blow spit bubbles during double French.

By the way, is it even possible to blow bubbles with spit, as in the sentence "blow spit bubbles"? or does it simply mean the boy likes to spit in a disgusting way ??

Answer 1

Traditionally in British schools lesson periods are 40 or 45 minutes long, but frequently one lesson will be scheduled on the timetable for two consecutive periods, which is known as "double (subject)" - double French, double maths, double science. (This comes up all the time in Harry Potter, for example, where he often has "double potions" or "double transfiguration".)

So here, they're talking about one French lesson that was 80 or 90 minutes long; obviously too boring for 11-year-olds who seem to find something else to do.

"Blowing spit bubbles" doesn't mean actual bubbles, just frothing the spit in and out of his mouth - but yes, in a disgusting way.