Dogs can understand 89 words on average.
A dog
Researchers in Canada surveyed more than 100 owners of various dog breeds about the words and phrases they can understand.
On average, owners reported that their dogs were capable of responding to 89 terms with one clever canine able to comprehend 215.
Almost all dogs were found to understand commands such as "sit", "down" and "stay" but the experts admit that formal training will be required for some dogs to understand as much as the brightest pooches.
Catherine Reeve and Sophie Jacques, who led the study at the Dalhousie University in Canada, said: "Due to their evolutionary history and close association with humans, domestic dogs have learned to respond to human verbal and nonverbal cues at a level unmatched by other species.
"Their ability to respond to communicative cues is critical for the numerous professional and family roles they play in our lives.
"Based on owner reports, dogs seem to vary greatly not only in the number but also in the kinds of words to which they purportedly respond."