Doubling 'r' in Spanish compound words

Question

Hola, amigos.

There appears to be a rule that when forming a compound word, if the second word begins with 'r', it is doubled.
Parece que hay una regla que cuando se forma una palabra compuesta, si la segunda palabra comienza con 'r', se duplica.

• mata + ratas = matarratas
• guarda + ropa = guardarropa
• para + rayos = pararrayos
• monte + rey = Monterrey
• etcétera (saltarrocas, quemarropa, altorrelieve,...)

I think this is to maintain the pronunciation of the 'r'.
Creo que esto es para mantener la pronunciación de la 'r'.

But... I cannot find this rule mentioned anywhere. Can you direct me to resources (preferably online) that mention this? In English or Spanish?
Pero ... no puedo encontrar esta regla mencionada en ninguna parte. ¿Pueden dirigirme a recursos (preferiblemente en línea) que mencionan esto? ¿En inglés o español?

Gracias.

Thank you for putting everything in English and Spanish. That helps with my learning.:) - Sassette, Jul 7, 2017

It doesn't help if my Spanish is wrong! - jtaniel, Jul 7, 2017

Answer 1

Although those are compound words, they become a new word and then the general rule applies. Look at rule #3 in the linked page.

Link to RAE

Thanks! - jtaniel, Jul 7, 2017

Answer 2

Here's a link. It seems you are right.

Forming Compound Words in Spanish

Words formed in this way are masculine, with rare exceptions, although they are sometimes used in the feminine if they refer to women or girls.

Also, the plural of these words is the same as the singular: a can opener is un abrelatas, but two or more are los abrelatas. If the noun part of the word begins with an r, it is typically changed to an rr, as in quemarropa from quema + ropa.

Although no collection of compound words can be complete, on the following page is a list of some of the most common along with many that have been included merely because they're humorous or otherwise interesting.

Thanks! - jtaniel, Jul 7, 2017

nice page - polenta1, Jul 7, 2017

Answer 3

Hello!

I'm not sure if these links from 2013 pertinent to this subject.

• The trilled r.
• Pronunciation of double r's in spanish

Hope this helps.

Regards!

Hi, NKM. Those questions are about pronunciation, and mine was about spelling. Thank you, though. - jtaniel, Jul 8, 2017