magical theory - Are spells in Harry Potter invented or discovered?

Are the spells in the magical world of Harry Potter invented or discovered?

Maybe someone just said “Avada Kedavra” and the rest is history.

Answer

While thinking over this question, I think spells must have been discovered. As we know, wizards and witches can perform magic unknowingly. Harry makes Aunt blow up like balloon, makes glass disappear in zoo.

So maybe in ancient time, certain people observed this unusual happening in their times and created a way to channel these powers out. This channel can be spells and wands their medium.

By considering this theory, we can say once the wizards and witches mastered this skill, they started combining raw spells to form more complex spells with more impact. Thus, some magical spells might have also been invented.

To Justify my case, lets assume 'Person A' getting unusual experiences like making flowers float. He shares this information with 'Person B' who claims that 'Person C' can make stones disappear for some time. 'Person A' and 'Person C' start experimenting and find way to control it, use it desired manner. Thus, Discovering spells. This knowledge spreads all over a certain region and people with unusual experiences form a group. They combine these spells in various formats to invent new spells.

From 1st movie, it is seen that even a mild flick of wand, Harry could spawn some random spells (Scene from Oliwanders Shop).