Step 1

 Era means was or were in the imperfect.
  It is an irregular form of ser.
   We use imperfect instead of preterite to refer
    to something with no definite beginning or end.

Yo patinaba cuando era niña.
      I used to skate when I was a girl.

Tú estudiabas en mi escuela cuando eras niño.
      You used to study in my school when you
       were a boy.

Él corría por mi casa cuando era joven.
      He used to run by my house when he was
       young.

Nosotros caminábamos a la escuela cuando
       eramos niños.
      We used to walk to school when we were
       children.

¿Vosotros cantábais en el coro cuando erais
       jóvenes?
      Did you all used to sing in the choir when you
       were young?

Ellos eran amigos cuando eran niños.
      They used to be friends when they were
       children.