The document discusses the key concepts the author learned about varieties of English throughout an English analysis course. The author learned about regional varieties characterized by dialects, social varieties divided among social groups, discourse varieties related to activities, and attitude varieties related to the speaker. The author also learned about standard English, including British and American variations, and the importance of understanding both standard and non-standard English. Reflecting on the course helped the author relate it to an English phonology course and understand why standard English is important to learn.