School level vs. learning level

[Levona]

Hi all!
I'm new in the field of teaching English as a Foreign Language. I currently have difficulty grading learners in the 6th until the 10th Grade into beginner, intermediate and advanced levels Is it safe to assume that 6th and 7th Grade are beginners, 8th and 9th Grade are intermediate, and that 10th Grade and upwards are advanced learners??
Thanks in advance.
Levona

[sastewart930]

My beginners (even though we don't exactly classify them like this)
have a range of about 4-5 years commonly. It's the same for the other levels as well. Much of this comes from how much learning they've experienced outside of their regular schools and (I hate to put it this way) but how smart and determined they are. I have had 10 year olds taking English class with 13-17 year olds and not struggling at all.