A SYNOPSIS OF ROLE AND REFERENCE GRAMMAR 145complement out of the AFD, resulting in a violation of the constraint in
(130). Evidence in support of this conclusion comes from speakers' reactions
to What did Truman Capote lisp that Bianca had bought?; those who know
that Truman Capote had a lisp find it as acceptable as (132a), and this is
because the choice of lisp is not particularly informative, given that piece of
background information. Thus the difference between (132a) and (132b) is
not structural in nature, but rather it follows from the influence of different
lexical semantic choices on the information structure of utterances.
The second type includes cases which in GB are subsumed under the
"empty category principle". Here again there is no violation of (111), and
yet question formation is precluded.
(133) a. Who did Mary say bought the house on the corner?
b. * Who did Mary say that bought the house on the corner?
While a complete RRG account of this phenomenon is beyond the scope of
this discussion, the general directions that such an account would take can
be sketched. Since the only overt difference between the two sentences in
(133) is the presence or absence of the complementizer that, the conditions
governing the occurrence of that and its effect on the complement clause
must be explained. It has been noted that the occurrence of that correlates
roughly with whether the complement is presupposed or not (e.g. Ertes-
chik-Shir & Lappin 1979), but it does not correlate with the possibility of
question formation, since there are verbs which require it, e.g. regret, but
which allow question formation out of post-verbal position, as in What does
Mary regret that John said?. There are three possibilities with respect to that
and question formation, summarized in (134).
(134) a. The verb requires that, and no question formation is possi
ble, e.g. (132b).
b. The verb requires that, and question formation is possible
from post-verbal position only (unmarked narrow focus),
e.g. regret.
The verb does not require that, and question formation is
possible from pre-verbal position (marked narrow focus)
when that is absent, e.g. (133a), and from post-verbal (un
marked narrow focus) position, regardless of the occurrence
of that, e.g. (132a).
The fact to be explained is the correlation of the overt complementizer and
the impossibility of marked narrow focus in the complement in English and