There is one language that people use in every country in the world. People who use it are young and old, short and tall, thin and fat. It's almost everybody's second language. It's easy to understand, but you can't hear it. It's sign language.
Babies who can't talk can point at things. They're using sign language. Sign language can be useful in places that are very noisy and in places that are very quiet. You can talk to the people who are behind windows. And when you go swimming with your friends, you can have a" "talk" under water!
Many years ago, a Frenchman wanted to help deaf people. He opened the first school for deaf people in Paris in 1760. And they learned sign language there. Teachers and doctors who wanted to help deaf people also went to Paris and had lessons. Then, they taught sign language to their students. Soon there were schools for deaf people in other countries.
Today, in the United States, there are special TV news programs for deaf people. The news broadcaster tells the news in sign language and the words appear on TV, too.