Prince Albert II, can be heard giggling in the background of the video.
This is the first time the royal twins have been heard speaking English as the pair attend a French school.
The Princess spoke to French magazine Point de Vue about the importance of her kids speaking more than one language.
She said: “This leads them to develop their own thinking, their own vision of things,' she said.
"Me, as their mother, I discover, I learn. I find it marvellous following their evolution, accompanying them on this path.”
She went on to reveal that the pair are best friends.
“Like all children they sometimes can be a little abrupt, a little hard even in their exchanges, but they support each other unconditionally. When all is well, then nothing and no one can stop them.”