I have been able to get every one of our dogs but Holly to speak. You just get them revved up with a treat they like, and keep saying speak, or what, and when they do it, and the first time will be a total fluke, you give them the treat. Once they do it, you keep at it. I have also taught them to whisper. They speak in their big voice, and I telling them ssshhhh, and when they tone it down, they get their goodie.
Thanks Ollie. This dog is a prize. We sure do love her!!!