Pluralize words ending in a tonic vowel

Question

I'm a native speaker. I'm pretty sure that the plural of tabú is tabúes, I've seen it used in writing, in the press. For similar reasons that the plural of marroquí is marroquíes.

I argued with someone recently about the pluralization of menú. Observe that champú, tabú and menú are are all words of foreign origin that end in a tonic (accented u). Identical rules should apply to them. I now know that menús is correct (and so is Microsoft's documentation for Office in spanish). The question is: is menúes acceptable? incorrect? How do you pluralize: champú, tabú and menú? Can someone explain to me the definitive rule? Is it plagued with exceptions?

Answer 1

There are four main cases to consider:

• When a noun ends in a tonic i or u, there are two accepted forms for the plural: one using -es and the other one using -s. For example: bisturíes o bisturís, carmesíes o carmesís, tisúes o tisús, tabúes o tabús.,The form ending in -es is preferred, so it is better to say bisturíes, carmesíes, tisúes, tabúes.

• In the case of gentilics, the plurals ending in -s are not considered incorrect, but the -es ending is preferred: israelíes, marroquíes, hindúes, bantúes.

• On the other side, some words from other languages only form their plural with -s: popurrís, champús, menús, tutús, vermús.

• The plural of the adverb sí, when used as a noun, is síes, but the plural of the musical note si is sis.

In your concrete examples, the correct plural forms are champús, tabúes (preferred) or tabús (accepted), and menús.

This information can be found in the literal c) of the entry for Plural of the Diccionario panhispánico de dudas.

Answer 2

En la mayoría de la veces, las palabras que terminan en í o ú tónicas admiten dos variantes para la formación del plural---con -s o con -es. Así es de que, se puede decir rubís o rubíes, tabús o tabúes, etc. Sin embargo, la palabra menú es una excepción, y se recomienda que la forma plural se escriba "menús". Yo sé que tales irregularidades son frustrantes.