speak when spoken to 

A phrase back in the day in which people would tell their children or wife to speak only when an adult begins to talk to you. In other words stay quiet.

Similar to the phrase stay quiet when the adults are talking.

Child comes up to parent and tries to speak while the parent is talking to then parent yells speak when spoken to.

speak when spoken to by Lovewithoutlife November 22, 2013

Speak when you are Spoken to or not at all 

A saying from an adult to a child usually when the child has interrupted the adult in the midst of their adult conversation with someone else.

I'm not talking to you therefore, hold your thoughts and speak when you are spoken to or not at all.

Speak when you are Spoken to or not at all by Diane1019 February 5, 2009