I was studying English while my family was watching TV.
I was crying while the light off.=  I was crying while the light was off.
He was yelling while she was gone.
They were teaching to children while the boy was standing.= They were teaching children while the boy was standing.

You're doing great using past continuous with “while” — nice job showing actions happening at the same time! Just watch for small grammar points like prepositions and verb forms to make your writing smoother.