What Are The Difficulties Of Teaching ESL, Or English As A Second Language?

The basic principle of ESL is that the learner's language is never spoken in the classroom, only English. This way, people of many different countries may be taught at the same times.
Some immigrants are literate in their own languages, but unfamiliar with the Roman alphabet. Others are not able to read or write in any language because of limited education or they came from countries that have only recently developed a written language.
Some students will be encountering English for the first time; others may have basic listening and speaking skills, but no ability to read or write English.
ESL instructor must remember that although the instruction is at the most basic level, students are adults. Therefore examples and lessons must not "talk down to," or patronize, learners, and must present real-life situations experienced by adults.
Most ESL students are there to enhance their employment skills and to learn words to deal with bureaucratic issues, like finding housing, getting a driver's license, obtaining medical care, and applying for public assistance. As such, ESL lessons must be immediately relevant to immigrants' lives.
Teachers must be aware of cultural differences. For example, it may be inappropriate for a woman to teach a man, or vice versa. Some societies place a high value on education, others much less so, so motivation may thus be affected. The shame of making a mistake differs by country, so initial emphasis should be on content, not grammatical correctness, so as to not overly discourage students.