The very best employers normally require full TEFL training obtained via programs that include at least 100 hours of training and a minimum of 6 hours of supervised practice teaching with classes of foreign students. The majority of overseas employers frequently recruit teachers who have no formal TEFL training. Courses that are shorter than 4 weeks or that are offered entirely via distance learning may help you to find a job with these employers. Courses involve lectures, seminars and ESL class observation. Some include supervised practice teaching with foreign students.
Some courses also provide supervised practice teaching .
MA degrees are widely accepted by US employers and are normally required for jobs with universities and colleges. Courses are comparatively long and expensive. Some courses provide little or no supervised hands-on training with foreign students. If you intend to make a career in TEFL, you will almost certainly need to obtain an MA at some point. However, it is probably best to start by taking a good TEFL certificate course.