Loki knows a good amount - enough for us anyway
The biggest reacting words are 'car ride', 'collar' and 'walk'. Those get his tail wagging and running towards the door we keep the collars and leashes hung up.
He also responds really well to 'C'est qui ca?' - that gets his ears really alert and running to the door and windows to try and see who is outside.
He also knows the basics, of course