-us-es? A Plural Revolution

The Revival of the Latin 4th Declension Plural

I like to write. It calms me. It provides a release. And, let’s be honest, it feeds my ego. All of these then are impet…. What? Impetuses? The snobbish out there would say that, technically, it should be impeti, as the plural of alumnus is alumni. But neither sounds good, even if one is correct. Impetuses hardly rolls off of the tongue, though that is the technically correct English plural.

But impetus is itself a Latin word, so what about impeti? The plural of alumnus is indeed alumni. The plural of focus is foci. Radius radii. Fungus fungi. But here’s where a little Latin knowledge becomes necessary. Latin nouns (like impetus, alumnus, focus, radius, fungus) are divided into five groups called declensions. All the declensions do is categorize the way different nouns behave. We don’t have declensions in English but if we did (or if you imagine learning English as a second language) you might be presented English nouns organized by how they form their plurals: one group adds an -s (noun → nouns); one group changes its vowel (mouse → mice); one group stays the same (fish → fish). The nouns whose plural is -i belong to the second declension. Impetus, however, is a fourth declension noun, so its (Latin) plural would not be -i.

The problem with the fourth declension plural, however, is that it is also -us: one impetus, many impetus. In spoken Latin, the two are pronounced differently: the singular as in the English bus, the plural a long -u like the sound in goose. So, phonetically, one impetus, many impetoose.

And how much more elegant is this? Certainly not the phonetic spelling but the pronunciation. I have many impetus (pronounced impetoose) for writing. Perhaps that is one impetus (pronounced impetus) too many. English already supports nouns with the same singular and plural form, so introducing the long -us (-oose) plural would not impact the clarity of writing (after, admittedly, a perhaps brief transition period). But it would both smooth and make more entertaining the spoken plural of these fourth declension nouns:

  • one impetus, many impetoose
  • one census, many censoose
  • one apparatus, many apparatoose
  • one status, many statoose
  • one fetus, many fetoose
  • one prospectus, many prospectoose (the Wikipedia site on English plurals, which is linked by a Princeton University grammar site, says for prospectus: ‘plural prospectus is rare although technically correct’; I wonder how it is pronounced….)
  • and I reproduce here three paragraphs from a 1993 column by Peter M. Ronai on Pitfalls in Medical Writing entitled “The Fourth Declension” from the American Journal of Roentgenology [another term for radiology] that describes other examples (and continues after these paragraphs to discuss the specific pitfalls of the noun adnexus).
Reproduction of part of p.1064 of AJR 1993.161.

And then there are the liminal nouns, those that end in -us but are neither second declension nor fourth declension. Octopus, sometimes pluralized as octopi, like impetus, is not a second declension Latin noun. But it is also not a fourth declension Latin noun. In fact, it is a calque from the Greek octopus, eight foot(ed), so its (Greek) plural would be octopodes. Another inelegant plural. So why not adopt the fourth declension plural in this case? “Was that an octopus that was chasing you?” “Eheu! Not just one octopus but three octopus (octopoose)! I barely got away.”

Similarly walrus comes to English by way, not of Latin, which the -us might suggest, but rather via Dutch walrus, itself a portmanteau of Dutch walvis (whale) and ros (horse), likely originating in Old Norse. The plural of walrus causes no little confusion, most dictionaries listing walrus or walruses as the plural (different dictionaries put each first) and some even including the Dutch plural: walrusser. Again, though, no pronunciation guide is offered for the plural. But the Latin fourth declension plural seems much more elegant (in a tongue-in-cheek way, of course). “I only see one walrus.” “Look over there. There are four more walrus (walroose) on the shore.”

So consider this the clarion call to action, to revive (vive?) the Latin fourth declension plural. Tell your friends. Tell your neighbors. Post it, like it, tweet it. It provides not only an elegant solution to some otherwise inelegant plurals (impetuses, censuses, fetuses) but also a vehicle to have a modicum of fun with some other of our plurals (even at the expense of technical correctness). After all, isn’t fun one of our primary impetus (which you should now be pronouncing correctly as impetoose) for writing and language?