Spanish has two forms of ‘you,’ the formal (usted [Ud.] ustedes [Uds.]) and the informal (tú, vosotros). There are no hard and fast rules for when to use one form or the other but, in general, if you know the person well enough to call him or her by his or her first name, use tú. If you address the person by Mr., Miss, or Mrs. with a last name, use usted (commonly abbreviated as Ud.) If you are unsure about which form to use, it is better to start off with usted. The native speaker can suggest that you use tú if it is more appropriate.

In Spain, a distinction is made between the plural forms ustedes (formal) and vosotros/vosotras (informal). In Spanish America, however, ustedes is used for both formal and informal situations. Use the plural whenever you are directly addressing more than one person.