if your first language is not english or if the language of instruction from your previous degree was not in English you will be asked to prove your command of the English language. You should have a TOEFL (Test of English as Foreign Language) with a minimum score pf 603 in the paper test, 250 in the computer-based test or 100 in the internet based test. Please visit www.ets.org/toefl
Alternatively you could have an IELTS (International English Language Testing System) with a minimum score of 6.5. Please visit www.ielts.org
These requirements vary depending on the university you are applying to so check their websites for more details. You are also encourage to take complementary language instruction before you enroll in your course so you get accustomed to English within an academic setting.