Subject-Verb agreement with compound subjects

[Carol]

Geoff Bannister wrote:
>  
> > Taking Madam Hooch's comment, I might have put it as: 
> > "I see a single broom in the air, the person riding it will be out
of Hogwarts before he or she can say 'Quidditch'!"
> > 
> > Old-fashioned, non-PC? Maybe. But I prefer the more accurate 
> grammar.
> 
> Potioncat:
> I'm older-fashioned. 
> 
> I prefer "I see a single broom in the air, the person riding it will
be out of Hogwarts before he can say 'Quidditch'!"
> 
> Just because I can't stand 'he or she'. I do sort of like the trend
in paranting magazines to alternate between  he and she. But I would
be quite content with the nonspecific 'he' to go along with the
generic 'you'.

Carol responds:

As an editor, I often have to reconstruct sentences so that they're
both grammatically correct and politically correct (many publishing
houses and style manuals have policies that discourage sexist
diction). I don't mind an occasional "he or she," but it's rather like
"one": Once one uses "one," one is stuck with "one," and I for one
happen to hate that particular pronoun (often a euphemism for "I," as
if "I" required a euphemism). Whenever possible, I try to rephrase the
sentence so that the referent (the noun referred to by the pronoun) is
plural. I might allow a "they" referring to a singular noun in
*dialogue*, depending on who is speaking, but I'd rather have an
ostensibly sexist generic "he" than a misused "they" in the narrative
portion of a novel (unless the narrator is supposed to be uneducated,
a la Huckleberry Finn) or the text of a nonfiction work.

With regard to Madam Hooch's sentence, I much prefer the original
version, "You leave those brooms where they are or you'll be out of
Hogwarts before you can say 'Quidditch'" (SS Am. ed. 147), which
solves the problem nicely, or, rather, avoids it altogether.

Carol, wondering what Madam Hooch thought of having her threat
completely undermined by Professor McGonagall, who rewarded Harry for
breaking her rule by making him the Gryffindor Seeker