Intellectual Lunches

Every once in a while at lunch, we will depart from our regular topics and discuss matters of great intellectual significance.  Generally, these departures take the form of some kind of grammar lesson (although yesterday I gave a lesson in distinguishing between the currencies of various Asian countries, which always comes in handy).

One day a few months ago, we had a particularly interesting (and funny) conversation.  In an e-mail thread between me, Bob, and Earl prior to lunch that day, I had used the term “ninjas” and then questioned whether the plural of “ninja” might be “ninji” (this was clearly a work-related e-mail thread).  While driving back from lunch, we had discussed this topic for several minutes with no consensus on the result when Earl suddenly posited, “Well, take the word Magi…” (as in "Gift of the...").  I was quite excited about where this statement might lead, as I don't believe I have ever heard the singular form of “Magi.”  Unfortunately, however, Earl's sentence trailed off when he realized that he, too, did not know the singular form of “Magi.”  Bob was no help, as he had never heard of Magi in any form. 

We spent the rest of the drive back to the office discussing plural forms of words that might use “I” at the end, such as radii (a special one containing two Is).  I've got to admit that I am a big fan of using an "I" ending as a plural in many situations in which it is not proper, just because I think "waitri" is a much cooler word than "waitresses."  Even though those words sound cool and, as such, I likely would not always follow the rule for proper "I plural" usage, it bothered me (and Bob and Earl) that we three highly-educated folks could not determine what the rule is. 

I called my sister that night because, even though she is prone to excessive "I plural" usage just as I am, she is also effing brilliant.  This is evidenced by the fact that, after I asked a totally out-of-the-blue question about an obscure grammar rule, she immediately busted up with this answer: "If the word ends in 'us' and is of Latin origin, the plural ends in 'i.'  If the word ends in 'us' and is not of Latin origin, the plural ends in 'es.'"  Now, she could just be making that up, but I'm going to give her the benefit of the doubt because she came up with the answer so quickly and because it sounds plausible.  Apparently this is something you learn when you deal with Latin medical terms (although I thought lawyers used a lot of Latin, too, but maybe that's just the litigators). 

Take, for example, the words alumnus and radius, which (as discussed above) become "alumni" and "radii" (my personal favorite).  The word bonus, however, becomes bonuses (although I plan to use "boni" from now on, because that is just a really cool word).  As a result of all this, I now propose that the singular form of "Magi" is "Magus."