Ernesto in El Salvador asks:
I would like to know what the correct form is: English teacher or teacher of English.
Both are correct, though "teacher of English" is more precise. An English teacher might be English by nationality and a teacher of biology, for example. But the majority of native-born English speakers would say "English teacher."
One reason I enjoy this blog is that questions like this make me think again about my own language. Imagine a headline: "English teachers are paid less than French teachers." Are we thinking about nationalities of teachers or the subjects they teach? We would need much more information to understand the meaning!