"exchange X for Y"

[Benjamin Zimmer]

Thomas Paikeday <thomaspaikeday at SPRINT.CA> wrote:
>
> Aren=92t we forgetting the essential meaning of "exchange =3D give and =
> receive reciprocally" as in all good dictionaries? If you read this =
> meaning into the text in question, we get: "to give porn and receive =
> Bibles in return."

Some dictionary definitions of "exchange", "replace", "swap", etc. may
imply that the reciprocal nature of such verbs means that the two VP
arguments can be freely ordered, but that ain't necessarily so. As
David Denison has written (see <http://tinyurl.com/cpmvr> for his
paper), Exchange verbs tend to use the pattern "OLD for NEW". The
exception is "substitute", though its traditional pattern of "NEW for
OLD" is now sometimes replaced by "OLD for NEW", probably due to
analogical influence from other Exchange verbs.

OED def 1b for "exchange" says: "with _for_ before the thing taken in
exchange". This definition expresses the ordering as "exchange THING
GIVEN for THING TAKEN"-- so that's homologous with "exchange OLD for
NEW" since something old is given up in return for receiving something
new. Of course, both sides of the exchange relationship may think of
the received items as "new", so we need to know whose perspective to
assume. As I said upthread, the assumed perspective is usually not
that of the initiator of the relationship who makes the offer of
exchange, but rather the "offeree".

In this particular case, students are offering to exchange old Bibles
for new porn. As Jon Lighter writes in another post, this appears to
be a parody of "cash-for-contraband exchanges"-- where the offer is
directed by a group seeking to replace something pernicious with
something benign. Compare also needle-exchange programs, which replace
dirty needles with clean needles, or the new face-saving initiatives
by Sony/BMG, which replace rootkit CDs with nonrootkit CDs. The
recipients in these exchange relationships are trading in OLD for NEW.
Hence the expectation (or at least mine) that the ordering should be
"Bibles for porn", not "porn for Bibles".


--Ben Zimmer