Colloquium with David Pesetsky (MIT)

Title:
Exfoliation: towards a derivational theory of clause size

Abstract:
We too easily become used to facts about language that should strike us as strange. One of these
is the menagerie of clause-types and clause-sizes in the world's languages categorized with illunderstood
labels such as finite, non-finite, full, reduced, defective, and worse. For almost a
half-century, the standard approach to these distinctions has treated them as a consequence of
lexical choice — a legacy of arguments by Kiparsky & Kiparsky (1970) and Bresnan (1972),
who showed (1) that verbs that select a clausal complement select for the complementizer and
finiteness of that complement, and (2) that finiteness and complementizer choice have semantic
implications. In an early-1970s model of grammar in which selection and semantic
interpretation were properties of Deep Structure, these discoveries directly entailed the lexicalist
view of clause type that is still the standard view today. So compelling was this argument at the
time, that its 1960s predecessor (Rosenbaum 1967) was all but forgotten — the idea that
distinctions are derivationally derived as the by-product of derivational processes such as
Raising. As a consequence, it has gone unnoticed that in a modern model of grammar, where
structure is built by Merge (and both selection and semantic interpretation are interspersed with
syntactic operations), the arguments against the derivational theory no longer go through.
In this talk, I present a series of arguments for a modernized return to a derivational theory. I
argue that a reduced clause is the response to specific situation: a clause-external probe that has
located a goal such as the subject in the upper phase of its CP-complement, when that goal does
not occupy the edge of its CP. Since anti-locality prevents that goal from moving to the clausal
edge (Erlewine 2015 and predecessors), a last-resort operation called Exfoliation deletes outer
layers of the clause until the goal occupies the edge without movement. If the goal was a subject
occupying a low enough position, the result is an infinitive. If the goal occupied a higher
position, the result is a finite clause missing its complementizer. My starting point is the
paradigm in (a)-(d). Because a standard approach assumes that every infinitive is born
infinitival, the contrast between (a) and (b) is usually treated as a puzzle of case theory: why does
moving the subject in (b) eliminate its case problem visible in (a)? The derivational approach
invites an entirely different question: why should the embedded clause in (a) be infinitival in the
first place? Since no probe targets the embedded subject in (a), Exfoliation should not have
taken place, and the clause should have remained finite (I assure you that Mary is the best
candidate). Only in (b), where an Ā-probe has targeted the embedded subject, is Exfoliation
justified, hence the possibility of an infinitive. Example (c) also shows Exfoliation, deleting only
the complementizer because the subject is higher than in (b), and (d) is impossible because no
Exfoliation took place — thus explaining the that-trace effect as part of the same paradigm.
a. *I assure you Mary to be the best candidate.
b. Mary, who I assure you __ to be the best candidate. (Kayne 1983)
c. Mary, who I assure you __ is the best candidate.
d. *Mary, who I assure you that __ is the best candidate.
Similar effects with A-movement arise in the behavior of English wager-class predicates and
raising in Lusaamia (Carstens & Diercks 2014), as well as with other Ā-phenomena such as anti-
Agreement (Baier 2015). Finally, I provide an independent argument for the last-resort nature of
Exfoliation from Zulu Hyper-Raising, based on a simplified version of a proposal by Halpert
(2015).