Teaching English as a Second Language is a high demand subject of instruction that continues to experience growth in schools across the country. As children from foreign countries continue to immigrate to the United States and enroll in schools here, the number of students whose native language is not English continues to grow. Thus, many schools have English Language Learners (ELL) programs, also known as English as a Second Language (ESL) and English for Speakers of Other Languages (ESOL). As the primary spoken language in a country with a rich history of immigration and cultural diversity, English and its mastery are na important part of educational development. ESL is offered for people of all ages, though it is not part of the standard public school curriculum as it is not essential to all students.