I am amazed by how many words my two girls understand. I have been adding new phrases and then matching it to an action. "Are you hungry, want some supper" means jump into the transfer box so you can go to the play area. There you will have your evening greens, get cuddled and brushed while sitting on mom's lap. "Back to your cage" means lay still so you can get picked up and returned to a clean cage and a pile of fresh hay. Last night my red and white girl actually jumped up on my lap when I said this. I was pretty excited. I told her what a good girl she was and immediately returned her to her cage. They know other words such as "Pat you", "Be brushed", "Treat". Before I started doing this they really didn't know what was coming next and therefore were not as trusting. As long as I am consistent they know when my hand comes into their cage what is going to happen. I would be interested into hearing some of the words your guinea pigs understand.