Re: Types of numerals

> Yes, linguists writing in English use "numeral" to mean
> "words for numbers", to distinguish from "number" usually short for
> "grammatical number" (singular, plural, etc.)
Well, I didn't know about that usage.  Of course, I'm not an actual
linguist.  Dadgum linguists -  always messin up language.   Say
they're just being descriptive, but at the same time they're modifying
whatever language they're doing their describing in. :)

> "Both" is to "two" as "???" is to "three", and so on.
> In some English writing from the 19th and early 20th
> centuries, "both" is used to mean "all three of", as well as "all two
> of".
> Might a series meaning
> "all two of" (both), "all three of", ..., "all n of", ...
> be useful?  How much of this series is attested in natlangs?
I don't know the answer.  It would seem to have limited utility; the
exact value of n in "all n of" seems less important, in general, than
the fact that it's "all" of the items under discussion.

Also, you asked what "halfth" vs "half" would be.  I can easily
imagine a formation analogous to "halfth" meaning something like "the
halfway point".  After all, many children will proudly tell you that
they are, for instance, four and a half years of age; that would imply
that they have passed their four-and-a-halfth birthday.    (I have
passed my thirty-seven-and-a-halfth birthday this past November and
will celebrate my thirty-seven-and-three-quartersth in February. :))

Of course, such a construct would probably be a later, learned
addition to the set of linguistic numerals.  Speaking of which: why do
you not consider "pi" to be a numeral in the linguistic sense?  It is
thoroughly lexicalized and probably more associated with the numerical
value than the letter of the Greek alphabet in the minds of most
Anglophones . . .