Forms are the groupings that Miss Mason used to separate students into different levels. They are based on developmental stages, and not ages, meaning they are supposed to be fluid and not rigid. A child moved from a lower form into an upper form when they were ready to handle deeper mental work.
Forms that cover more than one year start at the B level (beginner) and then progress to the A level (advanced). Within B and A levels, a form may be further subdivided into the lower level and the upper level. So in Form I, a student starts in Form IB, moves to Form IA Lower and then finishes with Form IA Upper.
In general, we have followed this pattern of forms:
Form III (12-13 years)
Form IV (14 years)
Form V (15-16 years)
Form VI (17 years)