In a clip posted to TikTok by user @farmer.lamb on September 14, Rex can be seen either smiling or snarling as his owner, Charles, lists his loves and hates.

So far, the post has received more than 810,000 likes and almost 30,000 shares, with one TikToker comparing Rex’s experience to an “emotional rollercoaster.”

Can Dogs Understand Words?

A 2021 study found that dogs can understand up to 215 words, after researchers from Dalhousie University in Halifax, Nova Scotia, studied 159 pets and their owners. The dogs reacted to between 15 and 215 words, with an average of 89 words recognized — roughly the same as an 18-month-old child.

The majority of dogs responded to their name and understood basic commands, such as “sit” and “stay.” Most dogs would wag their tail when hearing positive phrases, such as “good dog,” but a large number struggled with object names compared to commands.

The level of responsiveness to words and phrases varied with each dog, and researchers said that the animals most likely understood how to respond to certain words, rather than understanding the word itself.

‘Tractor’ Good, ‘Washing Machine’ Bad

In the video, Rex and his owner Charles are sitting in the front of his car. Rex’s ears perk up and he seems to grin at the word “tractor,” but is clearly unimpressed by the phrase “washing machine.”

Rex’s face also lights up at the word “car,” but the term “nom nom” causes him to snarl. “Defaid” (Welsh for “sheep”) gets a positive response, while “cer i’r gwely” (“go to bed”) leads to more growling.

TikTok users had their own opinions on Rex’s likes and dislikes. “Why is no nom bad?” wrote Nat, to which Charles replied, “I used to pretend to eat his feet when he was a pup.”

Beverly Wild wrote: “Why doesn’t he like the washing machine?” to which Charles replied, “That’s where his toys would go.”

“Why is ‘go to bed’ bad?” commented Kaitlin. “Is he sad he has to stop playing/having fun?”

“I like how he looks away when you say the bad words as if he’s having flashbacks,” wrote TikToker Avery.

“You had him on an emotional roller coaster,” commented Ryan Lawson, while Noe Postma wrote: “He sounds like he’s violently sighing, and it’s perfect.”

Newsweek has reached out to @farmer.lamb for comment.