a leisurely collection to entertain and instruct

  Frans Plank
 (Universität Konstanz)

with some items and/or languages brought to my attention by:
Michael Cysouw, Elena Filimonova, Orin Gensler, David Gil, Aditi Lahiri,
Wolfgang Schellinger, Pieter Seuren, Horst Simon

 last update: 9 October 2000

 send to:  frans.plank@uni-konstanz.de
 and visit:  http://ling.uni-konstanz.de/pages/proj/Sprachbau/rara.html

 Introductory Note

A Raritätenkabinett is a collection of things, living or more often dead, which are considered valuable,
or at any rate worth collecting and perhaps exhibiting, because they are rareónot such things, though, whose commodity or exchange value would grow with rareness, but ones whose very existence, contrary to experience or indeed reason, makes the beholder marvel at the design of the universe.

The rara, rarissima, and singularia collected here come from the realm of grammar, wondrous enough in its everyday manifestations.

A rarum is a trait (of any conceivable sort:  a form, a relationship between forms, a matching of form and meaning, a category, a construction, a rule, a constraint, a relationship between rules or constraints, ...) which is so uncommon across languages as not even to occur in all members of a single (middle to lower level) family or diffusion area (for short: sprachbund),
although it may occur in a few languages from a few different families or sprachbünde.
Diachronically speaking, a rarum is a trait which has only been retained, or only been innovated, in a few members of a single family or sprachbund or of a few of them.

Thus, on this definition, a trait may well be infrequent (an infrequentale, so to speak;  Latin purists might prefer infrequens) without being a rarum.  Just think of such precious family or (former) sprachbund possessions as syntactically governed word-initial segmental alternations, generally infrequent but omnipresent at least in Celtic and Berber (and also heard in Nias (Malayo-Polynesian, Austronesian) and in Iwaidja and Marrgu (Iwaidjan, Australian));  triliteral roots, found throughout Semitic and possibly Berber;  or clicks, shared by the entire Khoesan family, though outside only by some (former) Bantu neighbours as well as, at some distance, by Dahalo (Cushitic, Afroasiatic).
Presumably, however, allowances ought to be made for single-member families also being able to host rara rather than only infrequentalia.

A rarissimum is even rarer than a rarum.

A singulare (or, less highfalutinly, a nonesuch) is unique to individual languages.

A pink dot in front of an exhibit means a published universal is being infringed on
by a rarum/rarissimum/nonesuch, which naturally throws doubt on that universal, interpreted categorically;
black-dotted rara/rarissima/nonesuches are inoffensive.

If interested in universals, visit The Universals Archive at:

As yet, the documentation of the Raritätenkabinett leaves much to be desired:
often references are only given to secondary literature where a trait has been noted
as being rare, but not to original sources.  This will be remedied in future.

 NB:  Needless to add that, at this stage, claims of rarumhood, rarissimumhood, and nonesuchhood
should be considered no less tentative than ones of universality.