greenmanPut your money where your mouth is

This idiom means "to support what you say by paying for it, usually with money".

 

E.g.

We all say we want organic food, but we don't put our money where our mouth is— Todos decimos que queremos comida ecológica pero no estamos dispuestos a demostrarlo pagando más

If you think Barça are going to win, put your money where your mouth is. I bet you 50 euros they lose— Si crees que el Barça va a ganar, demúestralo. Te apuesto 50 euros a que pierden

John is always talking about starting a business, let's see if he puts his money where his mouth is— John siempre está hablando de montar un negocio, pero del dicho al hecho hay un buen trecho