Spanish Language Style Guide and Glossaries: Grammar

Below are examples and explanations for words, phrases, acronyms, numbers, punctuation, capitalization, symbols, and more used in Spanish grammar.

Abbreviations, Acronyms and Em Dash


  1. Incorrect Use: EE UU
  • Correct Use: EE. UU. (Estados Unidos)
  1. Incorrect Use: f.f. c.c.
  • Correct Use: FF. CC. (ferrocarriles)

Plural form of compound words, organization names or some countries are made by using double letters, as in ferrocarriles (FF. CC.) and Estados Unidos (EE. UU.).


  1. Incorrect Use: CD–ROM
  • Correct Use: CD–ROM (Compact Disk–Read Only Memory)
  1. Incorrect Use: E.U.A.
  • Correct Use: EUA
  1. Incorrect Use: O.N.U.
  • Correct Use: ONU

While periods are used in abbreviations of complex names (two or more words) to indicate different words, acronyms (siglas en español) do not use periods between the words.

Pluralization of Acronyms

Acronyms don’t add an “s” to denote plural when preceded by articles or words that denote plural, i.e. “los CD,” “muchas ONG.” However, in cases where there are no modifiers that denote plural, it may be acceptable to pluralize acronyms as in English: CDs, DVDs, PCs, ONGs. For example: “Reproducir DVDs en el equipo.”

Em Dash (—)

It is mainly used to indicate incidental sentences and speech openings in dialogues.

Incorrect Use

Son dos ciudades — Roma y Venecia

La traducción — Una ciencia empírica

Come—dijo ella—o llegaremos tarde

Me temo –comentó Juan- que da igual OR Me temo –comentó Juan–que da igual

Correct Use (or Lack of Use)

Son dos ciudades: Roma y Venecia

La traducción, una ciencia empírica

Come —dijo ella— o llegaremos tarde

Me temo —comentó Juan— que da igual

Spanish Language Capitalization

Titles in Spanish do not follow the capitalization style of the English language:

  • Fraudes de trabajo en el hogar
  • Work-at-Home Schemes

Do NOT Capitalize

Days of the week and months

  • In Spanish the days of the week and months of the year are written in lower case unless they are the first word in a sentence.

Languages and nationalities

  • Follow the same guidelines as days of the week and months.

Words in parentheses

Don’t capitalize unless the text in parentheses is an acronym. Examples:

  • TC (tomografía computada)
  • Red Mundial para la Búsqueda de Niños Desaparecidos (en inglés)
  • Culebrilla (herpes zoster)

Do Capitalize

First Word of a Title

  • Tipos de asistencia financiera para la universidad.

Names of People or Places (Proper Nouns)

  • Enfermedad de Still del adulto
  • Evite problemas en las aduanas cuando regresa a los Estados Unidos
  • Organización Internacional del Trabajo

First Word After a Colon (:)

  • When it is a quote (between quotations marks or not), or a list in several paragraphs, each one following a number or a letter

First Word After an Em (—) Dash

  • Enfermedad del corazón —Prevención

First Word After a Forward Slash (/)

  • Impuestos/Tributación
  • Desvío de las arterias coronarias/Angioplastia

Dates & Numbers


In Spanish, dates are expressed in this order: day, month, year (DDMMYYYY).

26 de octubre de 2004

26 octubre 2004


We recommend using the first two forms in the United States to avoid confusion with the American mode for reflecting dates.


The North American Academy of Spanish Language (, acting under the GSA-ANLE Agreement (PDF, 214 KB, 4 pages), recommends that the notation for decimals and fractions in Spanish texts published in the United States follow the American model. Nine Latin American countries also follow this model. The decision was based on the nomenclature used in the United States by banks, financial documents, commerce and the media.

Correct use in USA: $1,276.50

Incorrect use in USA: $1.276,59

Ordinal numbers

Commonly used:

Abbreviated ordinal numbers: 1ro. or 1º, 2do. or 2º, 3ro. or 3º…

Feminine gender case: 1ra. or 1ª, 2da. o 2ª, 3ra o 3ª …

Academic Spanish:

Abbreviated ordinal numbers: 1.º, 2.º, 3.º… 25.º… 100.º

Feminine gender case: 1.ª, 2.ª, 3.ª … 25.ª … 100.ª

Billions and Trillions

Much has been debated about these two terms and how to translate them into Spanish in the United States. To avoid confusion for Spanish speakers in the United States, a literal translation from English is recommended.

Translation in the United States

Billion = Billón (1,000,000,000)

Trillion = Trillón (1,000,000,000,000)

Translation for other countries or International Spanish

Billion (US English) = Mil millones (unidad seguida de nueve ceros)

Trillion (US English) = Billón (unidad seguida de doce ceros)

Meaning of these terms in the Diccionario de la Real Academia Española (DRAE)

Billón = Un millón de millones, que se expresa por la unidad seguida de doce ceros. (DRAE)

Trillón = Un millón de billones, que se expresa por la unidad seguida de 18 ceros. (DRAE)


Exclamation and Question Marks

In Spanish, exclamation and question marks open and close the desired phrase. The opening ones are inverted (¡) (¿) and the closing ones are the same as in English: (!) and (?):

  • ¡Hágalo en línea!
  • ¿Cómo puedo hacerme ciudadano estadounidense?

Punctuation marks are written outside of quotation marks, parenthesis and dashes.

  • Juventud, divino tesoro, ¡ya te vas para no volver!
  • El médico dijo: “La revisión se canceló; era previsible por el temor del paciente. Sin embargo, es probable que la cancelación no sea definitiva”; acto seguido, suspiró hondo y añadió: “El cáncer es curable en su diagnóstico precoz (las estadísticas lo confirman), la familia debe saberlo”.

Diacritics and HTML Code

Use of Diacritics

When using HTML, diacritics [los acentos gráficos] must be also coded. For example:

Página = Página

Spanish Accent Rules

Accent rules apply to both capital and lower case letters. For example:

Ácido fólico/ácido fólico

Última revisión/última revisión

Each character and its code is listed below:

Number Entity
á á á
é é é
í í í
ó ó ó
ñ ñ ñ
ú ú ú
ü ü ü
ª ª ª
º º º


Symbol HTML Entity
¿ ¿
¡ ¡
« «
» »
" &#quot; (to open and close)