A new study suggests that the first topic of human conversations, which led to the evolution of human language, centered on stone tools some 2.5 million years ago.

According to a joint study by researchers at UC Berkeley, the University of Liverpool and the University of St. Andrews, our human ancestors developed language to share how they crafted rocks into hunting tools.

To determine the link between Stone Age stone tools and the evolution of human language, the researchers focused their study on the oldest known cutting device, called Oldowan tools. They performed five experiments with 180 students in teaching modern humans the art of "Oldowan stone-knapping" in which hard rocks are hammered against volcanic rocks to create hunting tools or flakes.

The experiment showed that spoken language led to the best quality of stone tools compared to those made using nonverbal communication.

"If someone is trying to learn a skill that has lots of subtlety to it, it helps to engage with a teacher and have them correct you," Thomas Morgan, lead author of the study and a postdoctoral researcher in psychology at UC Berkeley, said in a press release. "You learn so much faster when someone is telling you what to do."

They believe that human language started evolving earlier than previously thought. Researchers estimated that the language took 1.8 million years to evolve as the Oldowan tools remained unchanged for 700,000 years.

"Our findings suggest that stone tools weren't just a product of human evolution, but actually drove it as well, creating the evolutionary advantage necessary for the development of modern human communication and teaching," said Morgan.

So what might have been the first sentence of our ancestors in the African savanna? Well, that could have been, "Tool bad," or possibly "yes," "no," "here" and "there," according to Discovery News.

The study was published in the Jan. 13 issue of Nature.