A SYNOPSIS OF ROLE AND REFERENCE GRAMMAR 143mation unit, in this case a predicative PP. Hence in both constructions the
subordinate clause in which the WH-word functions is necessarily outside of
the PFD and the resulting WH-questions are ill-formed. The sentence in
(129a), Who does he think stole the meat?, has the same structure as in Fig
ures 35 and 37; therefore the subordinate clause meets principle (111) and
is potentially in the PFD of the sentence, and the question is well-formed.
We may formulate the following general restriction on question formation
in complex sentences.
(130) General restriction on question formation: The element ques
tioned (the WH-word in a simple, direct WH-question or the
focal NP in a simple, direct yes-no question) must function in a
clause which is within the PFD of the sentence.^64
This restriction does not distinguish between question formation in lan
guages in which the WH-word appears in situ and those in which it appears
in the PCS; it therefore applies equally to Lakhota and to English. This
principle, together with (111), accounts for the examples looked at above and
two other well-known cases, noun complement constructions and sen
tential subjects. In a noun complement construction (see Figure 39), the
subordinate clause not only does not have a direct relation to the matrix
clause, as specified by (111), but it is also part of the internal structure of a
basic information unit, an NP. Hence it is outside the PFD of the sentence.
A sentential subject is a core argument of the verb, and, as the simplified
structural representation in Figure 50 shows, it does not meet (111) and is
Figure 50