In Spanish the personal pronoun "you" takes two forms: tú and usted (Ud.)
Tú.- is an informal or familiar way of addressing a friend or relative.
Usted.-Is a formal way of addressing people you meet for the first time, clients, or anyone in a higher position.
Vos.-this is the particular form in which argentinians adress a person.
Why should you invest your time learning Spanish? Here's an important reason. Spanish is spoken in really many countries around the world. If you are planning to visit any country in Latin America, speaking Spanish is a must to really enjoy your trip. Look at the following map.