Lately I have been frightened by how much our corgi Loki can understand of human speech. Just toying around, I found out he knows what we call his toys, and can retrieve the ones you tell him to. If you ask him where a toy is, and ask him to 'lead you to it' he will also bring you to it (works well for stuff that gets stuck like his beachball ((he loves herding it around, very vocal about it))). I find it kind of ridiculous how much he has picked up without being trained to do so explicitly.
Does your corgi do this?