Most pet dogs know a few words, but recently, the astonishing communicative skills of domestic dogs ( Canis familiaris ) have been discovered: Some dogs know a great number of words and differentiate objects by label in apparently humanlike ways. However, one must be careful not to overestimate the skills of man's best friend. At best, canine skills are comparable to the receptive language skills of 12– to 18-month-old infants—with grammatical skills being the most debated and questionable. One also must not underestimate their skills. Perhaps most strikingly, and in sharp contrast to other nonhuman species, from puppyhood, dogs of all breeds understand the pointing gesture.