The first day of classes, we developed different activities in which we discussed the fundamental principles of assessing second language learning. Those principles are validity, reliability, practicality, equivalency, and washback. It is very important to know each of these principles in order to have a better understanding of how assessment works when it is planned effectively. It should be said that probably not all the types of assessment comply with these principles, however, we as teachers should be aware of taking them into account when planning any assessing tool in the classroom.