 DIP TESOL, Diploma in Teaching English to Speakers of Other Languages DIP TESOL is an internationally recognized professional teaching qualification that is designed for teachers with some experience in the classroom. This certificate is widely considered to be a follow-up to the third TESOL certificate and is often taken by teachers in order to update and improve their existing English language teaching skills. The course is split into four sections and is assessed through a combination of examinations, coursework, and in-class assessment. The DIP TESOL certificate is seen as an equal to the DELTA certificate due to the similarity in the course syllabus. However, there are some differences in the moderation and assessment of each course. As with the CERC TESOL course, this certificate is awarded by Trinity College London.