Globally, people currently use roughly 7,500 languages, with English, Mandarin Chinese, Hindi, Spanish, Arabic and French the most common, counting native and nonnative speakers. They identified a period spanning the first millennium BC and first millennium AD when humankind may have spoken tens of thousands of different languages. The number topped out in a range from 30,000 to potentially more than 75,000 different languages used worldwide at any one time. “For scientists, languages carry huge amounts of information about the past, from where people lived to what they ate, and what they talked about. Many language families arose and evolved, with written language eventually emerging, first in Mesopotamia — Sumerian written in cuneiform script — during the fourth millennium BC, and separately in places like Egypt, China and Mesoamerica.