An English teacher: a person whose profession is teaching English, whether in schools, cram schools, or corporate settings.
私の姉は中学校で英語教師をしています。
My older sister works as an English teacher at a junior high school.
英語教師は生徒の会話力を伸ばすためにペアワークをよく取り入れる。
English teachers often incorporate pair work to improve students' speaking skills.
その学校は英語教師の数を増やして、授業を少人数制にした。
The school increased the number of English teachers and made classes smaller.