I have been a nursing instructor for years. Quite a number of students are Chinese and Vietnamese. Most who came in this country (US) had ESL education in their countries of origin, and it is a real challenge teaching them the language (no offense intended). The failure rate is so great. Probably the quality of education and the curriculum teaching the language need to be addressed ,as well as the quality of instructors. Not because someone can speak, read, and write english is qualified to teach (i.e. a european high school grad seeking a job as an ESL teacher in China, is qualified to teach because English is the native tongue. Da. ). And not because one is an experienced teacher means an effective one. This is just based on my opinion which came from dealing with the students.