Try to imagine attending a high school in a foreign country with very limited language knowledge. Even just imagining is hard! And I have just done that when I moved from Hungary to the USA! If you are planning on doing something similar read on!
When you are in a new place the key thing to remember is not to be introverted! Try to answer questions during classes (I know it’s hard when you can’t speak the language yet but try your best!), ask your classmates about the school, the classes, the teachers, the extracurricular activities they are involved in, what sports they are playing. This last one is always a winner since especially in the USA almost each and every student is involved in a team! So a perfect way to integrate, get to know people and make friends is to choose a sport and be part of a team! Also don’t be afraid to invite the people you might like to your home to hang out!
