Auxiliary Reduction: it all depends on the context

[Arnold M. Zwicky]

one of the better-studied features of english is Auxiliary Reduction
(or Contraction), and one thing that's been known about AuxRed for a
long time is that it's inapplicable in a large collection of
phrase-final contexts, for instance in cases like the following:

We should leave now.  Well, I know I am / *I'm.  And I hope you are /
*you're, too.

but now I come across things like the following, from the CSI tv
series.  in this scene, a CSI investigator, whose name is Kitty X (for
some X i didn't catch) is introducing herself to a complainant:

Kitty X, criminal investigator.  And you're?

technically, "you're" here is phrase-final, in fact sentence-final.
but what we have here is a kind of discourse ellipsis, with a final
rising intonation indicating that kitty's question is an invitation for
her interlocutor to fill in the blanks: "I'm NN."  this is just fine.

now, how to fit this observation into a more general account of the
conditions on AuxRed (as in the 1997 Pullum & Zwicky LSA paper whose
abstract can be found in the december LSA Bulletin), that's another
question.

arnold (zwicky at csli.stanford.edu)