GAHARU4D future-oriented TRINITY cOLLEGE LONDON CertTESOL Istanbul Centre… CertTESOL The Trinity Certificate in Teaching English to Speakers of Other Languages (CertTESOL) is a TESOL or TEFL (Teaching English as a Foreign Language) certificate designed for people with little or no experience of teaching English, and for those with experience who require an internationally recognised initial teacher […].