How to Teach a Language/English

When teaching English, there are considerations that don't necessarily apply to other languages. Because English is the de facto lingua franca of business, engineering, medicine, and aviation, it's the most commonly learned second language, and a significant number of English language learners will be speaking it not with native speakers, but with other non-native speakers. When teaching English, take into account your students, and consider your audience.

General English
Most of the classes you will be teaching are likely to be General English. When teaching these classes, it makes a significant difference whether your students are adults or children, and whether they are living in their country, in a country that speaks English, or in a country that speaks another language the students may not know.

English for specific purposes
There are a number of varieties of English for Specific purposes, and these generally require some sort of specific training, in addition to a TESOL certificate. The most common of these are Business English, and preparation for the Test Of English as a Foreign Language (TOEFL). English is the de facto language of the medical community, and the International Civil Aviation Organization requires all air-traffic controllers to have a minimum level of English. English for specific purposes often require you to have some training in the specific field.

TOEFL
Students studying in English-speaking countries, or universities where classes are taught in English need to prove that they can understand it. Which means that many colleges require the TOEFL: the Test of English as a Foreign Language.

Business English
Business English requires you to teach general economic terms, marketing terms, and business management terms.

Idioms
One of the most difficult things for English learners is English's large number of idioms--phrases that don't mean what they seem to mean. It helps to understand them, but you also need to consider when to teach them. Many of your students will use English only or primarily with other non-native speakers, and when this is the case, you can eliminate most idioms, with one important exception.

Phrasal Verbs
A specific kind of idiom is the phrasal verb, which is a verb, usually a fairly common one, combined with a preposition, used as a particle. If this seems difficult, don't worry. You use them from the time you wake up to the time you finally get up. You keep it up when you get going and head off to work, and you show up and clock in. When you knock off for the night and head out,  whether you meet up with some friends or go back home, you're using them again.

Phrasal verbs are unavoidable in English, and though you can try to keep them to a minimum, it's important that you understand how they work.