"When will I need to know this?"

[Eilonnwy]

You're only in High school? That explains a lot.

High school exists so you can have basic knowledge so you can get by in this world that ever more increasingly relies on people with knowledge. College is where you'll specialize and you can do it till your hearts content when you get in with the addition of some general ed.

You may have goals in your mind but be realistic. You want to study language, work hard, get into a good college.