The taste buds on the tongue are what tells the taste. The tongue has 4 tastes, which are well-known, and they are sweet, salty, sour and bitter. The taste buds on the tongue can tell the difference between these 4 basic tastes. The taste buds send signals to the brain and the brain tells you what you are tasting. A baby is born with taste buds on the sides of the tongue and the roof of their mouth. They disappear when a person gets older (on the roof of the mouth and the sides of the tongue), and mostly are just on the tongue.