As I teach in a school which has a very diverse population (South Florida), I have to deal with students of various language/understanding skills. As it mentions through this section, it helps to learn some words of the students' language. Since I am a multilingual speaker, I tend to bring out words the students will understand from their own language so they will understand the day's topic. It also helps that the classes I tend to teach tend to focus on topics which are close to most international/other language students.
