“We asked native Korean speakers to write down what they heard, and they understood him,” said Angela S. Stoeger, a biologist at the University of Vienna and one of the study’s authors. “We also compared his imitative vocalizations with that of other elephants, and it was very different.”

In fact, Koshik seems to imitate the pitch and timbre of human speech, and of his trainers in particular.

The researchers think that Koshik started imitating human speech out of a need to socialize. For seven years when he was a juvenile and at a critical stage in his development, he was the only elephant at Everland Zoo.

“He adapted vocalizations to his human companions, the only social contact he had,” Dr. Stoeger said.

It is not clear, however, how much Koshik understands, or whether he is capable of learning more. While he seems to know the meaning of “sit,” for instance, he does not expect his trainers to sit when he says the word himself.

“He’s basically using this as a social function, but not really to communicate with the keepers,” Dr. Stoeger said.

Since 2002, Koshik has had a female Asian elephant as a companion. Although he interacts and socializes with her using typical calls, he also continues to produce his Korean utterances with the people around him.

Previously, Dr. Stoeger and her colleagues discovered an African elephant that imitates the sound of truck engines and another African elephant that imitates the sounds of the Asian elephants that it grew up near.

This article has been revised to reflect the following correction:

Correction: November 2, 2012
The caption with an earlier version of this article misstated the given name of the University of Vienna researcher who described vocalizations by a young elephant in South Korea. She is Angela S. Stoeger, not Ashley.