In (60), the major syntactic break between NP and VP aligns perfectly with the major prosodic break and with the
major information structure break. Such an alignment or resonance among structures is highly favored in cognition,
and language goes out of its way to make it possible. For instance, as many writers have remarked, a major functional
motivationfor the passive construction is that it puts into subject position an intended topic that in the normal active
for mwould be postverbal.
The cognitive salience of the topic-comment form, I suspect, is what gave rise to the Aristotelian formulation of
logic in terms of predicates applied to subjects. In fact, it also likely accounts for the very use of the term“subject”
(=‘topic’) for the initial NP in a sentence (see discussion in Seuren 1998: 120–33). Lambrecht, again following Marty,
calls a sentence in topic-comment form acategorical judgment. In the present approach, of course, it is useful to notice
also the mismatches between syntax and information structure that the organization into tiers leads us to expect. Not
everysentencefallsso cleanlyintoeither thetheticor categoricaltype. For instance, thesubjectof(52a)(PAT went to the
party)is Focus rather than Topic, so the sentence is neither thetic nor categorical.
Weare nowconfrontedwithtwooverlappingnotions ofinformationstructure: thefocusispickedoutinoppositionto
the presupposition (which includes topic), and the topic is picked out in opposition to the comment (which includes
focus). To reconcile the two, I will use the term“common ground”specifically to designate the part of information
structure that is neither topic nor focus. In other words, the“presupposition”is an informal term for topic plus
common ground; the“comment”is common ground plus focus. Focus is obligatory, topic and common ground are
optional. If topic and common ground are both absent, the sentence expresses a thetic judgment.
One other piece of information structure needs to be mentioned. Consider answers to questions that contain twowh-
phrases.
(61)A: Who danced with who mat the party last night?
B: Well, FRAN danced with DAVID, ELI danced with FANIA, and ELIZABETH danced with BARBARA.
Following our treatment of answers to questions above, we would like to say that each of the highlighted NPs in B's
reply is a focus, hence that there are two