Hi Esta. I’ve been on both sides of the whole testing spectrum. I am an ACE University Instructor, and have also had to take many, many proficiency exams myself (certifications, GRE, LSAT exam, Bar exam…) I totally understand your uncertainty. Take solace in the fact that we can NEVER know everything that there is to know about any subject. Understanding concepts, systems and simply allowing yourself to become good at critically reading test questions (because unfortunately some test givers like to try to give us trick questions 🙂 will be your best preparation. Take sample tests and then say “enough, I’m ready!” Trust yourself and know that you’ve put in the time and effort to prepare.
I try to approach test preparation as I do physical training and preparation. Schedule the time to study and prepare. Give yourself a timeline and then when you reach the end of your prep time – TAKE THE TEST! One of our worst enemies (and allies) is our own mind. Don’t let doubt or fear keep you from taking that final step of taking the exam that you know you have done your best to prepare for, and like sports or any other endeavor, go into it KNOWING that you will not get EVERY question correct, and that “that’s ok.”
Good luck, you’ll be fine.