Working with teenagers is not an easy task. This seems to be a notion shared by language teachers all over the world. While some instructors are very keen on working with this special age group, others are not fond of the challenge. The truth is that teaching English as a Second/Foreign Language (ESL/EFL) to teens has never been easy. According to recent research in the neurosciences, the reasons for that may lie in the maturing brain of the adolescent. At their age, teens are undergoing many physical and cognitive changes that manifest themselves in the classroom. For example, teachers may have noticed that some teenage students talk non-stop and are usually not that enthusiastic about the activities planned for a lesson. What is worse is that even if students do cooperate, they can stay focused only if they manage not to fall asleep! In order to provide some understanding about this age group's typical behaviors, this article explores some of the changes that the brain undergoes during adolescence. Then it describes some activities and techniques to help teenagers stay focused and, hopefully, succeed in learning English. (Contains 1 figure.)