ESL (English as a Second Language) refers to English as a Second Language courses, mainly for students whose mother tongue is not English. Generally speaking, according to the level of English proficiency, ESL courses in Canadian high schools are divided into five levels from low (level 1) to high (level 5). Students who have reached ESL Level 5 have language proficiency close to that of native English speakers, with no major problems in listening, speaking, reading, and writing.

Reflects the importance of ESL courses for non-English speaking students only after the adoption of the appropriate level of ESL exam to be eligible to learn the local high school English curriculum. ESL courses are based on the syllabus of Canadian public schools, so that non-native English students can reach the same level of Canadian high school students in terms of English listening, speaking, reading, and writing, and promote the rapid integration of non-English speaking students with Canadian university courses.