Teaching a language is a science and a skill. It is a science in the sense that it is a systematically organized body of knowledge on a particular subject. A science that is majorly fed by two other fields of science: Psychology and Linguistics. And also, it is a skill, an ability to do something well.
Nowadays, most universities other than taking a long time to cover these subjects, normally a post graduate course, tend to cover literature, linguistics, or translation as their major discipline, not teaching. So what happens is that a university student learns a language while studying one of the majors we mentioned. But is that what you need in a classroom environment?
TESOL courses, we provide you with 120 hours of intensive study on science and skills of teaching. Five terms, each term being 12 sessions in 4 weeks. There will be a week recess in between the terms. And upon the completion of the course you are required to pass a test. After successful completion of the test, you will be presented with a certificate which should enable you to teach anywhere in the world.