Sixth grade. According to the relevant information, EF TB6 is the sixth level in EF's children's English course, which is suitable for students around 10- 13 years old. Ef education EFTrailblazers English course is an English course for children aged 10- 13. Pioneers mean "leaders", that is, leaders with original spirit. They advocate an advanced idea or lead a group of followers, and they are usually regarded as "people on the road to success".