1. (

• along ,
• on

) with a forward motion; "we drove along admiring the view"; "the horse trotted along at a steady pace"; "the circus traveled on to the next city"; "move along"; "march on" ;

2. (

• on ,

) indicates continuity or persistence or concentration; "his spirit lives on"; "shall I read on?" ;

3. (

• on ,

) in a state required for something to function or be effective; "turn the lights on"; "get a load on" ;