Plurals of loan words

Question

Are there any rules for forming the plurals of loanwords?

I ask, as I was recently reminded of a sign I saw in an Office Depot in Mexico advertising "mouses".

Can this be correct in Spanish, or is it proper form to use the English plural "mice" in this case? If "mouses" is proper in this case, are there other examples where the plural form is also borrowed from an original language, but the Spanish plural would be considered incorrect?

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NOTE: I know we're guilty of the same class of error in English, when we talk about a single tamale.

Answer 1

There are rules for extranjerismos:

• Palabras terminadas en -l,-r,-n,-d,-z,-j. Forman el plural en -es: píxeles, másteres, pines, raides, interfaces, sijes. Se exceptúan las palabras esdrújulas, que permanecen invariables en plural: los trávelin, los cáterin.
• Palabras terminadas en -s,-x,-ch. Algunas se mantienen invariables (campus, sioux); otras hacen el plural en -es (valses, faxes, sándwiches).
• Palabras terminadas en consonantes distintas de -l,-r,-n,-d,-z,-j,-s,-x,-ch. Hacen el plural en -s: esnobs, chips, cómics. Se exceptúa el término imam, cuya forma plural es imames. La palabra club tiene dos plurales: clubs y clubes.
• Palabras terminadas en dos o más consonantes. Hacen el plural en -s: gongs, icebergs, récords. Se exceptúan las palabras test, trust y kibutz, que permanecen invariables en plural, y los términos lord y milord, cuyos plurales son lores y milores, respectivamente. También se excluyen las palabras acabadas en consonante + s, que hacen el plural en -es (valses) permanecen invariables (fórceps).

Your word "mouse" is not a major problem as it ends in vowel, so it would apply the normal rule to add an -s.

Answer 2

This is an anglicism. I cannot speak of all Spanish speaking countries but in Mexico it is very common that people use the English word for some computer terms, in this case "mouse" and instead of using the Spanish word "ratón".

The problem is that a lot of people think that that is the actual name of the device and they pluralize it as if it were a Spanish word which, of course, is not correct, but it has now become the common way of calling it.