What is an English teacher?

Answer 1

From Wikipedia - http://en.wikipedia.org/wiki/101_(number)

At universities in Australia, Canada, South Africa, and the United States, often the course number of basic or entry-level courses is 101. By extension, it is informally used elsewhere to indicate things that are meant for beginners. At universities with four-digit course numbers, the equivalent course number is 1001 or 1010. A "crash course." An example would be English 101, its the same thing as remedial English or Crash Course of English. This usage is not common in the United Kingdom.

So basically, "English 101" means "English for Beginners".

Answer 2

English class are classes that teachs people english.

Answer 3

a person who teaches english.