One of the endearing things about Shelties is how fast they learn our words.. I mean we have even had trouble spelling words so as not to evoke a response and some times that didn't even work. The word Treat is a game changer, when we ask where is the cat both dogs start looking for the cat..was it a border collie who knew the names of 100 of his toys and could pick them out of a piles of toys and recently read of a dog who knew 1100 nouns had just died... I wonder how many of us know dog bark language as well and who is the smarter??