Another day and another pair of similar-looking Spanish nouns with different endings and genders whose different meanings and usage may be worth spelling out. These are siglo (masculine) and sigla (feminine).
You can listen to how siglo (masculine) is pronounced here:

Un siglo is a period of one hundred years – a century:
a finales del siglo pasado
at the end of the last century
Este proceso empezó hace siglos.
This process began centuries ago.
In English we identify centuries using ordinal numbers before century (for example, the 19th / 20th / 21st etc century); in oral Spanish, however, normal cardinal numbers are used after siglo, but they’re written in Roman numerals (for example, el siglo IX / XX / XXI etc):
en las últimas décadas del siglo XX (read as siglo veinte)
in the last decades of the 20th century
durante el último cuarto del siglo XIX (read as siglo diecinueve)
in the last quarter of the 19th century
El siglo is also used to talk about the period in which something significant flourished or arose. In this case, it is often translated as the age:
el siglo de la Filosofía / Ciencia
the Age of Philosophy / Science
Siglos is also translated as ages when used informally to mean a long time:
¡Hace siglos que no nos vemos!
We haven’t seen each other for ages!
An interesting Spanish expression is por los siglos de los siglos (for ever and ever or for ever more):
Así ha sido siempre y seguramente así continuará siendo por los siglos de los siglos.
That’s the way it’s always been, and doubtless it will go on like that for ever more.
Turning to sigla (feminine) you can listen to how it’s pronounced here:

Una sigla is an abbreviated name for something:
- This may be a new word formed from the initial letters of something (an acronym):
La sigla OTAN significa la Organización del Tratado del Atlántico Norte.
The acronym or abbreviation NATO means the North Atlantic Treaty Organization.
- Equally una sigla may be a name formed of initial letters pronounced as letters (an initialism or abbreviation):
la sigla PP
the abbreviation or initialism PP
Las siglas (in the plural) are also the initial letters that make up an acronym or initialism:
El ordenador personal es más conocido por sus siglas en inglés: PC.
The personal computer is better known by its abbreviation or initial letters in English: PC.
Nueva York puede identificarse con las siglas NY precedidas de una I y un corazón.
New York can be identified by the abbreviation or letters ‘NY’ preceded by ‘I’ and a heart.
DID YOU KNOW?
When plural names such as Estados Unidos (United States), Juegos Olímpicos (Olympic Games) and Fuerzas Armadas (Armed Forces) are abbreviated in Spanish, the plural aspect of the abbreviation is indicated by doubling each of the initial letters and using full stops after the second one in each case:
los EE.UU.
the US
los JJ.OO.
the Olympic Games
las FF.AA.
the Armed Forces.
Join us next week as we go over the different uses of some more similar-looking Spanish nouns.