Trinity Diploma in TESOL (DELTA equivalent)

Gain your advanced qualification in ELT with Europe's leading course provider - now available fully online

The Diploma in Teaching English to Speakers of Other Languages (DipTESOL) is equivalent to a Cambridge Delta and is an internationally respected qualification for experienced teachers of ESOL/EFL. Having the DipTESOL enables teachers to move into roles such as examiners, coursebook writers, teacher trainers and school managers. Gain your Trinity DipTESOL qualification with us and advance your career in ELT.

Course summary:

  • Blended or Fully Online: Choose between studying 7 months online followed by 4 weeks face-to-face (in Barcelona, Cádiz, Hong Kong or Kerala) or studying fully online.
  • Practical: Emphasis throughout the course on developing teaching skills and applying insights to your classroom.
  • Phonology: Emphasis on teaching pronunciation unique to the Trinity course and highly valued by our graduates.
  • Flexible: Work at times to suit your weekly schedule (10-15 hours per week). Take up to 3 years to complete the course if necessary.
  • Professional: Learn from world-class full-time and guest tutors including Lindsay Clandfield, Scott Thornbury, Nicola Meldrum and Adrian Underhill.
  • Supportive: Receive unlimited support via email and Zoom from our Course Director.
  • Transformational: Develop your teaching skills and improve your chances of finding some of the best positions in ELT via our careers service.
  • Recognised: Gain a prestigious, internationally recognized and advanced qualification in ELT.

Our DipTESOL tutors

Who is this course for?

The Trinity Diploma in TESOL is for English Language teachers (including primary and secondary school teachers) who…

  • have at least two years of full-time experience or equivalent (960 hours).
  • work in the private or public sector with language schools, universities or teaching privately.
  • are looking for an advanced professional qualification in English Language Teaching.

What do our graduates say?

What is the course like?

Wherever you are in the world, you can gain this qualification. In 2021, we are offering even more flexibility with the format. Choose from two ways to take this course:

Option 1 (Blended): 7 months part-time online + 4 weeks intensive face-to-face training including teaching practice in Barcelona, Cádiz, Kerala or Hong Kong (see dates here).

Assessment: Unit 1 (in a registered centre), Unit 2 (Online), Unit 3 and 4 (in Barcelona, Cádiz, Kerala or Hong Kong). In the case of restrictions due to Covid-19, you will have the option to switch to Option 2 (below) to do units 3 and 4 online.

Option 2 (Fully Online): 7 months part-time online + 4 weeks intensive online training including your teaching practice (see dates here).

Assessment: Unit 1 (in a registered centre), Units 2, 3 and 4 (Online).

1. The 7-month part-time online phase

  • Seven months of part-time online training in our virtual classroom with fellow teachers and our team of tutors, participating in forums, webinars, live video classes and email exchanges.
  • Twenty, week-long modules (with some rest weeks in between) led by one of our tutor team. You are expected to contribute regularly, but the interaction is not scheduled (other than a 45-minute live video class), so you can log into the course throughout the week to suit your own working day.
  • Weekly assignments which help you comprehensively prepare for exams and receive written feedback from your tutor so that you can visualise your development and performance against Trinity’s benchmark. 
  • In total, you will complete around 350 hours of study and support during this phase (50 hours per month).
  • Start in January, April or October

What can I expect to learn during the part-time phase?

Our goal is to provide a course which is dynamic and practical and meets the needs of the participants, so your work in our virtual classroom will be backed up with tasks which get you to apply ideas in your own classroom. With a team of highly experienced and qualified tutors, the online modules will help you to deepen your theoretical knowledge and practical skills while preparing for the four assessed units of the Trinity DipTESOL course:

  • Unit 1: Teacher Development and Language Awareness
  • Unit 2: Research projects
  • Unit 3: Phonology
  • Unit 4: Teaching practice

Read the full course syllabus

2. The 4-week intensive phase


  • 4-week intensive teaching practice phase including lesson planning, teaching practice and feedback from our expert team of tutors.
  • Choose to complete this phase face-to-face in one of our centres or fully online.
  • You will have four internally assessed lessons and one externally with a Trinity examiner. You will also have an opportunity to teach unassessed to get to know the students and get feedback and advice from tutors.
  • External assessment of phonology and teaching practice with Trinity examiner.
  • Including lesson planning time, you will be studying for around 40–50 hours per week during the four weeks.

What can I expect during the intensive phase?

If you choose our blended study option, you will complete your unit 3 phonology interview and unit 4 teaching practice assessment during a four-week phase in Barcelona, Cádiz, Kerala or Hong Kong. You will deliver your classes to adult students in one of our centres and receive support from our tutors who will be with you in the school.

If you choose our online study option you will complete your unit 3 phonology interview and unit 4 teaching practice assessment online. You will deliver your classes to adult students using Zoom and receive support from our tutors online. We can provide the students for you, or you can use your own students.

In both cases, there are various options for dates.

How will I be assessed?

There are four assessed units on The Trinity DipTESOL course. Unit 1 and Unit 3 are assessed by Trinity College and Unit 2 and Unit 4 by Trinity College and OxfordTEFL together.

  • Unit 1 (face-to-face): This is a written exam which is completed over three hours and consists of a grammar section and two sections with essay questions about teaching and learning. In 2021, if you take the 4-week intensive phase online, this is the only assessment for which you would need to attend a centre—all other training and assessment can be provided online. The unit 1 exam can be taken at one of our locations (Barcelona, Cádiz, Kerala, or Hong Kong) or at any centre which is authorized to run the Trinity DipTESOL, CertTESOL, or TYLEC courses (check herehere, and here).
  • Unit 2 (online): This is a coursework portfolio including three action research projects. The projects involve observation of other trained teachers, reflection on your own teaching and a research project where you collect data. The expertise of your tutor will be matched to your chosen field. Work on the portfolio will be completed throughout the course. You will need to base the reflection task on teaching a group or groups of at least six students for fifteen hours in total. Your portfolio will be submitted online.
  • Unit 3 (face-to-face or online): This is a 30-minute face-to-face or online interview with a Trinity examiner on phonetics and phonology.
  • Unit 4 (face-to-face or online): This is an assessment of your face-to-face or online teaching of five one-hour lessons, each preceded by a discussion of your lesson plan (10 minutes) and followed by a discussion of the lesson with the examiner (20 minutes). Four lessons are assessed by Oxford TEFL tutors, the fifth by a Trinity examiner. 

The qualification

Once you have completed the course and passed the assessments you will be awarded the Trinity Diploma in TESOL. This is an internationally recognized and respected advanced professional qualification for English Language Teaching. Many UK universities are now offering credits and/or exemptions on their MA and other courses for those who have obtained their DipTESOL.

This qualification opens doors into other areas of the ELT profession. Our graduates have gone on to become:

See the required reading list for this course

Careers Service

  • We are committed to providing our graduates with the best lifelong careers support possible. We work with you before, during and after the course to help you secure a new job if that is your aim.
  • Since 1998, we have helped over 4000 of our graduates find work all over the world. We have an Oxford TEFL Jobs Facebook page which is updated regularly with jobs around the world.
  • You can also stay in touch with our community of teachers, trainers and graduates by joining our Trinity DipTESOL Facebook group (exclusively for our teachers, graduates and trainers).

Read more about our Careers Service

Still have questions?

Meet Rubens, one of our expert tutors, as he answers some of the most common questions about this course. Find out why this course is a great step in your career.


Step 1: Complete the application form.

Step 2: You will be contacted within one working day to arrange an online interview with the Course Director. We will ask you about your teaching experience and language awareness to help decide whether this course is suitable for you. The interview is also an opportunity for you to ask questions about the course and decide if it is right for you.

Step 3: If your interview is successful, we will email you a full place offer with information about how to reserve your place on the course by paying your deposit.

All of the fees for the course can be found on our Diploma dates and prices page.


At least two years full-time teaching experience or equivalent (960 hours) teaching English as a Foreign or Second Language. The experience can be with any age group or in any teaching context.


A Certificate in TESOL/CELTA and a degree or proof that you would be able to cope with a course of study at post-degree level.

We offer two start dates per year: January and October. 

We are also able to run alternative dates/locations where there are a minimum of 6 teachers interested. (For example in the cases of teachers from the same school or network of schools)

Experiences from graduates