Why Spanish Uses ‘EE. UU.’ as the Abbreviation for ‘United States’

Estados Unidos protest sign

Gerald Erichsen is a Spanish language expert who has created Spanish lessons for ThoughtCo since 1998.

Updated on July 30, 2024

Once you learn that Estados Unidos is Spanish for "United States," you might predict that its abbreviation would be EU, just as we often use "U.S." (or "USA") in English. But, believe it or not, the standard abbreviation in Spanish is EE. UU.

The Rule for Plural Abbreviations in Spanish

Although the abbreviation for the U.S. may seem unusual to Spanish students, abbreviations like it are common in standard written Spanish when shortening plural forms. Although the use of the periods in the abbreviation is standard usage and considered mandatory by some authorities, it isn't unusual to see the abbreviation without the periods: EEUU or EE UU. Sometimes the abbreviation EUA (for Estados Unidos de América) is used, and even USA can be found in trendy circles.

Basically, the doubled letters (such abbreviations are called abreviaturas dobles in Spanish) are used to indicate that the main word abbreviated is plural. However, such a doubling of letters isn't needed if the plural word isn't the main noun in the phrase. For example, Organización de las Naciones Unidas (United Nations) is ONU ("U.N." in English.) The main noun here, the one that gives the phrase its gender, is singular: organización.

The doubling of letters comes from Latin, which explains some of the double-letter Latin abbreviations used in English also, such as "pp." for "pages" and "mss." for "manuscripts." Identical abbreviations are used in Spanish: pp. for páginas and mss. for manuscritos. (Also commonly used is págs. for páginas.)

Such doubling is used typically when a single letter stands for a word. It isn't used used for most other abbreviations. For example, while ejemplo (example) can be abbreviated as ej., the plural form (that is, for "examples") is ejs. Similarly, while usted (singular you) is abbreviated Ud., its plural form (plural you) is Uds.

One of the exceptions is that the abbreviation for Buenos Aires (the city in Argentina) is Bs. As.

Other Doubled Abbreviations

Here are some of the other Spanish abbreviations that double the letters in the same way as EE. UU.:

Other Unusual Abbreviations

Spanish also has a few common abbreviations that use punctuation (other than the period) or superscripts in ways that English doesn't. The more common ones are listed below; in many cases, more conventional forms are often used in addition to these.

Additionally, there are some forms such as Abg. da and Dr. a that have been used to refer to a female lawyer or doctor, respectively, although these are growing in disfavor.

Key Takeaways