Cat got your tongue? How our pets creep into our conversations

I was a shy, quiet child, so the phrase I heard most often from my grandmother was "What's the matter? Cat got your tongue?"

It wasn't until much later than I started to think about where this — and other pet-related phrases — came from.

It seems like this saying should have a colorful history, but its origins are as shy as I was. Its first known appearance in print was in Ballou's Monthly Magazine in 1881, where it was described as a phrase said by children. But some references suggest that the phrase dates to the Middle Ages, when it was thought that a witch's cat would steal or control the tongue of anyone who saw the witch in action.

Cats play a big part in other popular (or once popular) terms and phrases.

Take cool cat, which entered our lexicon in the 1940s, when it was associated with jazz music. But, according to the Oxford English Dictionary, slang references to people as cats predates the jazz age.

And what about letting the cat out of the bag? This idiom, referring to spilling a secret, has no clear origin, but Barbara Mikkelson of the urban folklore website Snopes.com wrote that "it could have to do with a similarity between the behavior of both secrets and cats — once either is let out, they go wherever they want."

Late summer is known for its dog days, or days of scorching heat. The dog days occur when Sirius, also known as the dog star, shines brightly in the sky.

Using the term black dog has a long history as a metaphor for depression. In Roman times, black dogs had negative connotations. The poet Horace wrote that the sight of a black dog with puppies was a bad omen. In the 18th century, wordsmith Samuel Johnson used the phrase black dog to describe his melancholia, and Brewer's Dictionary of Phrase and Fable listed the saying "a black dog has walked over him" to describe a sullen person. In the 20th century, British Prime Minister Winston Churchill used the phrase black dog to refer to his own depression.

And don't we all wish we could live a dog's life? Then again, maybe not. In its earliest known reference, a 16th-century manuscript, a dog's life referred to a miserably unhappy existence.