I bet it heavily depends on teachers and curriculum. I had English classes from first grade and at the end of school I was fluent in written and spoken English.

I bet it heavily depends on teachers and curriculum. I had English classes from first grade and at the end of school I was fluent in written and spoken English. But the curriculum was not even close to what they teach in most schools. It was pretty hardcore. The groups were small (10 students max) and the teachers were relentless and actually cared.