Irregular IR-class verbs, or why I’m not losing weight

So embarrassing–I had a great opportunity to use an obscure IR-class verb (mincir, meaning to lose weight or to make you look thin) yesterday, but in the first person singular present tense, not the third person plural present tense that we worked on last time–and I blew it.  Attempting to explain the connection between the delicious French-Canadian dish called poutine–fries covered with cheese curds and gravy–and why I’m not losing weight, I conjugated it as an ER verb, not IR.  !@#$%$!  I guess I just gotta work on those IR-class verbs some more.  So, for the moment let’s just point out that there’s a Montréal restaurant, La Banquise, that serves 25 different kinds of poutine, agree amongst ourselves that I’ll go there this week when I visit our neighbors under the Big Red Maple Leaf, and focus on irregular IR verbs.

In that spirit, let’s look at the present tense of some irregular IR verbs.  In the singular forms, the final written consonant is the same, but where the regular IR verbs have the vowel i in front of that consonant, the irregular IR verbs do not. We’ll use finir (to finish) as our prototype of a regular IR verb–all of the other verbs in these tables are irregular IR verbs:

In the plural forms, the regular IR verbs (like finir) and the irregular verbs (all of the other verbs in this post) are quite different, and actually look a lot like ER verbs:

Similar verbs include mentir (to lie), sentir (to smell), and compounds of all of these.

How many verbs like this are there? It’s surprisingly difficult to say. It’s even unclear what exactly “this” means. The traditional answer would be “the set of third-conjugation verbs,” but “third-conjugation verbs” include a number of verbs of entirely different classes. Just looking at the example verbs on this page, there’s a clear difference between verbs like courir and verbs like dormir–they share the same endings, sure, but the stem of the verbs like dormir lose a consonant in the singular forms.  Would you count mourir?  The endings are the same, but there’s a change in the stem vowel.  How about démentir (to deny)?  It’s conjugated like mentir,  but while the past participle menti is invariable, the past participle of démentir can be inflected for gender, and be démenti or démentie.  Does it count as like “this”?  And, there are words related to the words that I’ve used as examples here.  For example, related to courir (to run), we have (from the web site L’Obs–la conjugaison):

parcourir – encourir – discourir – accourir – concourir – recourir – secourir

Counting word types is always an ugly business–this shows you one thing that contributes to that kind of ugliness.  Mincir (to lose weight) is totally regular, by the way, although at this point in my life, for me to lose weight would, unfortunately, be quite irregular.