With over two decades of experience in the ELT field, Sergio Pantoja has worked as a teacher, teacher trainer, speaking and writing examiner. He holds, among others, a degree in Languages, a postgraduate degree in English Language Teaching and Translation, a TESOL Certificate from the University of Oregon, USA, the C2 Proficiency certificate (CPE), and the Delta. His Delta Module 3 Specialism focused on LDT (Language Development for Teachers). Sérgio is the author of three books.