Some languages have more than one word for “you” based on how many people the word “you” refers to. The **singular** form refers to one person, and the **plural** form refers to more than one person. Some languages also have a **dual** form which refers to two people, and some have other forms that refer to three or four people.
Some languages have more than one form of “you” based on the relationship between the speaker and the person he is talking to. People use the **formal** form of “you” when speaking to someone who is older, or has higher authority, or is someone they do not know very well. People use the **informal** form when speaking to someone who is not older, or does not have higher authority, or is a family member or close friend.