the human tongue is about 10 centimeters long. it is covered with taste buds which are tiny nerve endings which enable us to taste our food. babies are born with taste buds all over their mouths. these gradually disappear as they grow old, leaving only those on the tongue. an adult has about 1000 taste buds. we can taste our food when saliva dissolves chemicals in the food and washes them over the taste buds. the four basic tastes are sweet, sour, salt and bitter. sweet tastes, such as sugar, are best detected by the taste buds at the tip of the tongue. salt is detected by those at the front sides of the tongue. sour tastes such as lemon can be detected by the taste buds along the edges at the back of the tongue. bitter tastes such as coffee can be detecred by those on the back of the tongue. there are no taste buds in the centre of the tongue. the tongue is also used in speaking. sounds are made in the vocal cords in the throat. the combined action of the tongue, throat, mouth and lips changes the sounds into words