Perhaps I am too much of a rational mind, but I must confess
I am frequently confused by what I regard as inconsistent uses
of grammatical person and number in pronouns. For example,
the use of the plural they or their to refer to a single person,
as in the Twitter screenshot below, always has me wonder—
if for only an instant—who this plural might be referring to.
The fact that such usage has become common does not seem
to help: I still find it illogical and would welcome an alternative.
I would have no problem with his or her in the above example,
but it is usually possible to avoid the issue through rewriting:
how about This person's tweets are protected or, to focus on
the audience, You do not have access to this person's tweets?
Granted, some constructions are more confusing than others,
whether with they or with any other pronoun. A few years ago,
I had a discussion with a US faculty about what person to use
after some of us: she insisted we had to use the first person,
not the third, and I maintain it changed the sense. Compare,
as an example, Some of us must manage their money better
with Some of us must manage our money better and imagine
that us is a club and some is meant with Jack and Jill in mind.
Wouldn't you agree that their refers to Jack and Jill's money,
whereas our designates the club's funds? Not the same thing.
The most amusing case of mismatched grammatical persons
I came across has got to be this health alert about H1N1 flu
(the picture was taken at Hobby Airport in Houston, Texas):
So, next time you see me cough or sneeze, remember to cover
my mouth and nose with a tissue (and to wash my hands, too).