Hi, Alexander!  Recently you wrote in a message to All:   
      
            You've asked some excellent questions here.  Although I'm starting in   
   the middle, my intention is to group the other ideas about articles together &   
   deal with them later.  This one is a bit more complex....  :-)   
      
      
      
   JKR>  Though Ministry spokeswizards have hitherto refused even   
   JKR>  to confirm the existence of such a place, a growing number   
   JKR>  of the Wizarding community believe that the Death Eaters   
   JKR>  now serving sentences in Azkaban for trespass and attempted   
   JKR>  theft were attempting to steal a prophecy.   
      
   ak>   look: A GROWING NUMBER ... believe that...   
      
   ak>   What the hell is this? It must be "believes" if you put "a"   
   ak>   before "number"   
      
      
            In most circumstances, yes.  When (a) noun + of + plural is used as a   
   collective noun, however, it may be treated as singular or plural depending on   
   whether the group is regarded as a unit or as a group of individuals.  I think   
   the latter is preferable in this context if the novelist wants us to empathize   
   with the "growing number" who are quietly (or not so quietly) wondering what's   
   going on.  The Ministry spin doctors & prisoners aren't treated as individuals   
   ... but they're less likely to be people Harry sees on a daily basis.  And now   
   the stage is set for Harry & his friends to help unravel the mystery....  :-))   
      
            FOWLER'S estimates that there are 200+ collective nouns in English...   
   not counting names for groups of animals, such as "a gaggle of geese".  If you   
   don't know the animals personally it is usual but not required to think of the   
   group as a unit.  The same also applies to human beings in words like "crowd",   
   "audience", and "government"... but FOWLER'S adds that in US English the rules   
   are more strict than in British English & that such groups would less often be   
   treated grammatically as comprised of individual persons.  Rowling is British,   
   and therefore more at liberty to use her own discretion WRT stylistic matters.   
      
      
      
            FWIW, I grew up on stuff like the following:   
      
      
                    I've got a lovely bunch of coconuts.   
                    There they are all standing in a row.   
      
                                         Fred Heatherton, ca. 1949   
      
      
                    A bunch of the boys were whooping it up   
                    In the Malamute Saloon....   
      
                                         Robert W. Service, ca. 1905   
      
      
   In the first example, the speaker is running a coconut shy (a carnival game in   
   which the objective is to knock over the coconuts).  He describes the sizes of   
   the coconuts in his booth & has possibly selected them himself.  In the second   
   example, the narrator lives in Whitehorse... i.e. a small enough place in 1905   
   that he'd have a pretty good idea who'd be in a saloon on Saturday night.  ;-)   
      
      
      
      
   --- timEd/386 1.10.y2k+   
    * Origin: Wits' End, Vancouver CANADA (1:153/716)