Essay and Multiple Choice Tests

I believe that both essay tests and multiple-choice tests are nothing without the other. If I were to give my class a multiple choice test am I really finding out whether they have grasped the concept of the subject? Without adding on essay questions I can never really be sure whether the students are just making random guesses at the answers or if they truly understand what is being asked. Essay questions allow me to see that not only did the student grasp the topic, but they can also explain it in their own words. It is important to know that the class is comprehending the material as well as memorizing it.