Students Abroad vs. in the U.S.
There are an estimated 550 languages spoken in the world today, and if you are working in TESL, either in the U.S. or abroad, your specific style of teaching, when it really comes down to it, will depend upon the native language of your students and the particularities and common mistakes that arise due to their understanding of language (based on their native language).
Basically, there are two types of ESL teachers who go abroad, who might want to teach English in China or South Korea for instance. One is the type of ESL teacher who is interested in a travel-filled year abroad, soaking up another culture, and putting as little effort as possible into his teaching, meaning no TEFL certificate and little to no real knowledge of grammar.
The other type of teacher is the one who is really interested in giving their students a valuable experience in each lesson, thinks of them each night as they carefully put together a lesson plan, considers individual progress of the students, and has goals he or she hopes to achieve with the students by the end of the teaching term. This teacher may or may not hold a TEFL degree and may not start out with any memory of articles and compound sentences, but is determined to research and study as long as it takes to get up to speed and have a super solid foundation from which to teach and confidently answer questions from.
So you can BS your way through a few months of teaching, and your students may have fun, but will they remember any English?
If you are teaching in the U.S., it is more likely that you are truly interested in language and have a passion for teaching, whereas those who go abroad for a few months often find teaching English simply an easy, fast way to make a little money for traveling, but have no initial, serious interest in teaching English for short term or long term.
So use your understanding of linguistics to sculpt your teaching style. Use your knowledge of your students' background to understand why they are learning English in the first place. If you do not know exactly, find out. Especially in small classes, it is important to learn about each individual student and his or her history and goals. And of course they will be curious about you as well, so take the time to answer their questions about your own life, your background and experiences, your hobbies, your goals.
If teaching ESL in the U.S., your class will more than likely be comprised of a mix of nationalities and therefore languages (what you may hear termed a 'nontraditional student population' by some schools and universities), something that will rarely happen if you teach abroad - after all you are living in the 'melting pot' nation. However, the range of nationalities in your class will also depend on where in the U.S. you are located, as your students will tend to be native Spanish speakers if you teach in the southwestern states.
In this kind of 'nontraditional' situation, some things are easier for you as a teacher: you are in your own home, no culture shock to worry about. No, in this case, it will be your students who are undergoing culture shock. If you are teaching a night class for adults in ESL at a community college, some may have been here for a year or less, while others may have been here for a decade or more. Regardless of the length of their residence in the U.S., they have all been adjusting to American culture in their own unique way, and the fact that they still need much help in speaking proper English is a sign that they are still constantly speaking in their native tongue when they are at home.
Most of your students are in your classroom because they are immigrants who need better English skills to get a job or find a better job; to pass a citizenship test; to get into a degree program at a university; or just to improve English for use in their everyday lives and be able to pass it onto their children and other family members that might be living with them. They are already living in an English-speaking environment, but their typical daily interaction with native speakers probably does not meet their needs, and that is why they are coming to you. You are responsible for helping them to accumulate a wider range of vocabulary, a deeper understanding of grammar and idioms, and a higher level of confidence in speaking. Teachers of immigrants to the U.S. bear a heavier burden than an ESL teacher abroad due this very reason: teaching an immigrant to use correct grammar is not the only thing they need to know about living in the U.S. It can become difficult not to feel the responsibility for their livelihood, their ability to land a good job, to pass the citizenship test or to be admitted into a university. If you find yourself thinking that more can be done than just teaching English, then you might want to look into other positions offered at an adult education center or social services center.
NOTE - Check out this volunteer teaching abroad page in our Volunteering Overseas section.
If you are working with adults who are as old or older than you, expect to be harassed from time to time by picky questions and comments that might mean they are sizing you up. Don't be disrespectful, but do politely and firmly emphasize that they are here to learn from you, and at least in your classroom, you are in charge. If you don't know your stuff, and this happens to many of the fresh college grads who teach for easy money who don't have a TEFL or don't know anything about the rules of grammar, your students will find you out eventually. This can happen in a classroom setting or in a one on one. You need to know your strengths and choose your classes based on them. Don't lie to your employer about your teaching experience and English grammar knowledge! If you have no interest (or memory!) in present continuous and past perfect simple verb tenses, then don't sign up to teach anything below the upper-intermediate level, because it is the beginners and pre-intermediate levels that will ask you the most grammar questions. In fact, focus your efforts on obtaining lessons with very small groups or, even better, individuals, who are interested mostly in practicing conversational skills.