Don't Confuse These: Discover & Invent
Let's discuss another pair of confusing words.
Marie Curie discovered radioactivity.
Did radioactivity exist before Marie Curie discovered it? Of course it did! She just found it out.
So, to discover something means to find out something which already exists.
Alexander Bell invented the telephone.
Did the telephone exist before that? Nope, it didn't.
So, to invent means to make something new, something that hadn't existed before that moment.
Who invented the radio?
Who discovered gravity?