The concept of class struggle is central to Marxist theory.

She is very class-conscious and always looks down on people from lower social classes.

The workers' strike was a clear demonstration of their class-consciousness.

She always stays at high-class hotels when she travels.

He decided to cut a class last Friday to attend a music festival.

He decided to skip class to catch his favorite band live.

He was promoted to private first class after completing his basic training.

The sergeant first class led the platoon into battle.

The petty officer first class is responsible for supervising and training junior enlisted personnel.

The petty officer second class is responsible for training and supervising junior enlisted personnel.