Translation of contagious in Spanish

I want to improve my level of English. Have you ever been in the U.S. and in which states have you been? I've been in England, Scotland and Ireland, but unfortunately, I have never been to America.
Please explain me the exact differences between British and American .... This year I'm trying to make the TOEFL. We can then discuss how we can prepare for this exam. I failed the first time.
When I wanted to do my homework, I accidentally landed on Vocabulix and it caught me right from the beginning. Connecting with other users can be brilliant. Skyping with them, chatting and messaging. Great idea.