Why is English class so important in high school? 

I could write a lengthy list of each reason English class is important but the bottom line of all those reasons is that it makes you a much better communicator.  In the adult world, being able to communicate with others is key to a successful career and most importantly a happy and productive life.

ALL of your classes, though, contribute to this; it's not just English class!  No matter the subject area, taking a wide-range of classes in high school helps you to become a critical thinker and a problem-solver!  You may not have any intention of becoming a chemist or a musician or a novelist, but LEARNING about many different subjects CAN help you think more deeply and communicate more clearly with others.  

Learning for the sake of learning is key!  You may excel in one area over the others but embrace those classes and concepts that challenge you, because new knowledge is what will make you SHINE!