Those have to be two separate classes, because they get changed under different circumstances.

They did not perform as well, and are sometimes considered a separate class.

They performed much less well, and are sometimes considered a separate class.

They sometimes benefited them in other ways, which led to the development of a separate class.

Students in the separate class may be working at different academic levels.

She is the only one of her friends to be put into a separate class in their second year.

The school itself opened in 1903 with separate classes for both boys and girls.

But when they did not make enough progress, the school decided to give them another year with her in a separate class.

There will be separate classes in school, maybe even different schools.

Then each age group will hold a separate class for instruction.