Question

When significa cuando y va siempre seguido de tiempo pasado simple, mientras que while que significa mientras, va siempre seguido de past continuous.
While une dos acciones simultáneas
La idea sería: mientras estaba sucediendo una cosa pasó otra.
Recuerda que el past continuous se forma con : was/ were + un verbo con terminación ing. ​

Answer 1

Respuesta:

While my grandmother was dusting the house, my mother answered the door.

When my mother answered the door, my grandmother was dusting the house.

While Sandra was looking throught the window, the postman came.

When the postman came, Sandra was looking throught the window.

While Sally was seing the postman, my uncle spoke with me.

When my uncle spoke with me, Sally was seing the postman.

While the dog was barking, my mother answered the door.

When my mother answered the door,  the dog was barking.

:)