386 MARY L. NUNES
explication of the pre-nominal genitive NP. Rather, it is the notion of topic
which defines the function of the LDP NP in English.
According to Deane (1987) in his analysis of English possessives, topi
cal NPs include information which is central but backgrounded in discourse,
generally reflecting what the discourse is about. Typically, such information
either has been referred to previously in discourse or is inferrable from the
context. In the English clause, the "subject" is most frequently a topic.
Lambrecht (1987) attributes this typical "subjecf'-topic alignment to the
relationship existing in many languages (including English) between infor
mation structure and grammatical form. This is a relationship in which the
function of the unmarked "predicate focus" structure of sentences (un
marked in terms of both grammar and discourse) is "to express a topic-com
ment relation, i.e. a relation of aboutness between the referent of the sub
ject and the proposition expressed in the sentence" (1987: 374). This "rela
tion of aboutness" obtains only if the "subject" referent is sufficiently acces
sible (cognitively and pragmatically) in the discourse to be pragmatically
presupposed. Otherwise, the "subject" occurs as what Lambrecht identifies
as a "presented NP" in a marked "sentence focus" structure, a structure
which is used to "introduce an NP referent, or the concept associated with
some NP, into the universe of discourse" (1987: 375).^12
Common to both Deane's and Lambrecht's definitions of topic are the
notions of "aboutness" and backgrounded presupposability. Crucially,
these notions pertain to both the referent of the unmarked clausal "subject"
and the nominal's pre-vN genitive NP. In the RRG framework, however,
the typically-shared topical status of the clausal "subject" NP and the pre-
nominal genitive NP does not reflect a shared GR. Rather, the prenominal
genitive NP is associated with a grammatically optional syntactic position,
the LDP, which bears no GR.
Unlike the referent of an English clausal "subject," an LDP phrase,
roughly functioning as an extra-clausal topic in the sentence, is grammati
cally optional in both S and NP. That is, when an LDP phrase is deleted,
neither type of construction is rendered ungrammatical, even though a
change in emphasis — or, in the case of vNs like destruction, in process-
vs. result-nominal status — occurs:
(11) Deletable LDP Phrases in the Sentence
a. Fred, I haven't seen him.
b. I haven t seen him/Fred.
At the White House, what did Gray destroy yesterday?