We do not always need words to say something. A smile says I am happy. A frown says I am upset. Waving a hand says hello or goodbye. Putting a finger on the lips says be quiet. A nod means yes, and shaking the head means no. These signs made with the face, hands, and body are called gestures and expressions. Even babies and animals use them: a dog wags its tail when it is happy and puts its tail down when it is afraid.
Some people who cannot hear use a full language of hand signs called sign language. Each hand shape stands for a word or a letter, and people can tell whole stories with their hands. People who cannot see read with their fingertips using Braille, a system of raised dots invented by Louis Braille. In classical Indian dance such as Bharatanatyam, dancers use hand shapes called mudras to tell stories without a single word. Traffic police use hand signals, cricket umpires use gestures for out and six, and a referee uses a whistle. Signs help us understand each other across different languages.
Example: Play a mime game with friends. Without speaking, act out feeling hungry, being cold, calling someone to come, and asking for water. See who can guess correctly. Then learn to sign your name in the finger alphabet.