Feminine genitive plural happens to have the same suffix as feminine singular, and it could be possible to envision an future evolution of the language where the genitive is lost, while the number agreement rule could be preserve. So it's possible that grammars of this future language would state that feminine plural agreement for numbers >=5 you have to use the feminine singular.
Btw, I once read a very nice title of a german language book:
"Der Dativ is dem Genitiv sein Tot"
literaly, "the dative is [to] the genitive its death"
Which denotes the fact that in modern German the genitive case is being lost in faviour of constructs based on dative (the correct form would be "Der Dativ ist der Tod des Genitivs", i.e. "the dative is the death of the genitive")
(http://en.wikipedia.org/wiki/Der_Dativ_ist_dem_Genitiv_sein_...)
IIRC, Finnish has something like 28 noun cases. That is intimidating.
Finnish (and other agglutinative languages) use suffixes to express many concepts that in English are expressed with prepositions: imagine if instead of "in my room" you would have to say "room-my-in" and you would call this the noun case of "containment" or something similar, the number of cases would go up pretty quickly.
It's not actually that complicated, most are simple suffixes - so for example, instead of on the table in Finnish you say table-on (pöydällä). Once you learn the rules of vowel harmony and consonant mutation it's a pretty regular, straightforward language.
As for cases: I am learning hungarian which is related to finnish and also has more than 20 cases.
The problem, in my personal experience, is that learning such an agglutinative language is slightly harder than others because when you are learning you don't know all the suffixes and at the same time you don't even know enough vocabulary to understand what's what. Especially once you consider that suffixes stack up.
I see something like "ccddee" and it's hard to understand where I should break up the thing (<ccd,dee>, <cc,dd,ee>, <cc,dde,e> etc). YMMV :)
hungarian is not related to finnish, rather to turkic languages. i am a native hungarian speaker, and i know hungarian grammar is logically closer to turkish than to finnish. the story how they became related is purely political, and references easily found on this subject and i do not intend to get into. in hungarian literature class we studied finnish words that were similar, grammer, and a few poems.
"" The Uralic languages ( /jʊˈrælɨk/) (sometimes referred to as Uralian languages) constitute a language family of some three dozen languages spoken by approximately 25 million people. The healthiest Uralic languages in terms of the number of native speakers are Hungarian, Finnish, Estonian, Mari and Udmurt. ""
i will not comment any further on this thread. my view is based on extensive research of turkish, finnish, hungarian, english, german, spanish, and russian grammers.
الكتب books(definite) حضراء green(feminine singular indefinite)