Language

Language is the system humans use to share thoughts with each other. Every human group on Earth has a language. People use language to ask questions, tell stories, give directions, joke, argue, and pass knowledge from one person to the next. Language can be spoken with the mouth, written with symbols, or signed with the hands.

There are about 7,000 languages spoken in the world today. The most common one is Mandarin Chinese, with more than a billion speakers. English, Spanish, Hindi, and Arabic each have hundreds of millions of speakers. At the other end, some languages are spoken by only a few elderly people in a single village. When the last speaker of a language dies, the language dies with them.

Languages come in families. Languages in the same family share an ancient ancestor, the way cousins share a grandparent. English, Spanish, Russian, Hindi, and Persian all belong to the Indo-European family. They all grew out of a single language spoken about 6,000 years ago, long before writing was invented. Scholars figured this out by spotting words that sound alike across languages. The English word "mother," the Spanish "madre," and the Hindi "mata" all come from the same old root.

How does language work? Each language has sounds, words, and rules for putting words together. The rules are called grammar. Kids learn these rules without being taught. By age five, most children can speak their first language well, even though no one ever sat them down to explain the grammar. Scientists are still trying to understand how the brain pulls this off.

Writing came much later than speech. Humans have been talking for at least 100,000 years, but the oldest writing is only about 5,400 years old. It started in ancient Mesopotamia, where people pressed symbols into wet clay. Today, different languages use very different writing systems. English uses an alphabet of 26 letters. Russian uses a different alphabet called Cyrillic. Chinese uses thousands of characters, where each character stands for a word or part of a word.

Sign languages are full languages too, with their own grammar and vocabulary. American Sign Language is not just English with hand signs. It is its own language, and a person who knows only spoken English cannot understand it.

Language is one of the things that makes humans different from every other animal on Earth.