It is quite common actually for a family to speak their native language at home to the kids so that the kids are fluent in that language and then when the child starts school or daycare, they learn English or French. Many parents choose not to introduce the dominant language too soon because they want to be sure that their children have a good grasp of the native language first and that it is not lost in the new culture. He will learn quickly and as the others said, if you could get some of the basic words from the parents, then you will be able to understand some of his basic needs while he is learning.