Sitting Stance- Feet in line, same direction, both knees bend equally. 
 

Front Stance - Feet shoulder width apart, and keeping feet facing front, one foot forward 3 foot lengths with that front knee bent keeping back one straight.
 

Back Stance - L shaped start heels on one line so one foot forward, one foot sideways. Front foot is extended forward with both knees bending but back knee is bent more.