Subject as a Probe
Akiko Kobayashi
Shimane University

1. Relativized Probing
Probe and goal are relative notions: when α and β have some matching feature, the c-commanding
one is the probe and the c-commanded one is the goal. This is explicitly stated in Chomsky (2000,2004, 2008) when he explains how expletive there and T undergo Agree. When generated in SPECof finite T, the expletive (D) probes its c-commanding domain T’ and finds T as a goal. When it
moves successive-cyclically, higher T is the probe for the expletive. “Apparent Spec-H relations arein reality head-head relations involving minimal search (local c-command)” (Chomsky (2004: 113)).
I suggest that all subjects in SPEC-T be the probe for T at the phase level. It is a necessaryconsequence of recent minimalist assumptions. Consider (1):(1) a. [TP T [v*P John v*-buy [VP tV a book]]]]b. [CP C [TP John T [v*P tJohn v*-buy [VP tV a book]]]]When the derivation has reached the stage (1a), T (probe) and John (goal) match but feature
valuation must wait until the phase level (Chomsky (2007, 2008)). T searches for a matching goalagain at the phase level (1b). But the search fails since traces are invisible (Chomsky (2000, 2001,2008)). For feature valuation, then, John in SPEC-T must be the probe for T.
An apparent problem arises when the subject is complex. Take The boy bought a book forexample. Since neither D (the) nor T c-commands the other, Agree cannot be established betweenthem. But there is a way out of this problem:(2) Transfer applies to DP when it is moved to SPEC-T.
By the application of Transfer, the internal structure of the DP is made invisible. But the label D
cannot be made invisible since it would tamper with the Merge relation between D(P) and T(P) (cf.
Chomsky (2000: 136)). Since a label “is always a head” (Chomsky (2004: 109)), the transferred DP
becomes identical with D. Hence the label D (the) can probe T’ and find T.
If this is correct, then, D (the label of transferred DP) is the probe when DP moves to SPEC-T, but
T is the probe when DP remains in v(*)P. Given this analysis, a variety of syntactic facts are given asimple, unified account.

2. Number Paradox(3) a. A man and a woman {are/*is} in the house.
b. There {is/*are} a man and a woman in the house.

(Bošković (1997: 87))

The verb agrees only with the first conjunct when the conjoined phrase remains in vP. The relativized
probing analysis explains this fact as follows, adopting Bošković’s (1997) BP (Boolean phrase)assumption. B takes two conjuncts and somehow adds up them. Each conjunct may bear a [Singular(Sg)]-feature but the BP bears a [Sg+Sg=Plural (Pl)]-feature. If the BP remains in vP, T finds thehead of the first conjunct (D) as the closest goal. (T cannot see [Pl] since it is held by a phrase.) On
the other hand, if the BP moves to SPEC-T, it undergoes Transfer and the label B involving [Pl]becomes the probe. The preverbal coordinated subject therefore triggers plural agreement.

3. Person Paradox(4) a. There {is/*am} only me.
b. There are only us .

(Chomsky (2000: 149, note 90))

Baker (2011) observes that in many languages DP triggers person agreement on head X only when itoccupies SPEC-X. The relativized probing analysis can account for this fact, given the common
assumption that pronouns have a complex structure (Déchaine and Wiltschko (2002), Chomsky(2012)). Based on independent evidence, I suggest that D may bear [Number (Nr), Gender (Gr)] but
not [Person (Pn)], which is associated with a lower head. A full φ-set is located at the level of DP as aresult of feature percolation. When a pronoun DP remains in vP, T can only see and agree with [Nr,Gr] of D. On the other hand, when the pronoun moves to SPEC-T, undergoing Transfer, the label Dwith a full φ-set becomes a probe and triggers full agreement.

4. (The Absence of) Subject Island Effects
In English, PP-extraction is allowed from the object but not from the subject. The asymmetry isexplained as follows. An internal argument DP need not undergo Transfer when it moves to theobject position (SPEC-V) since it is a goal for v*-V. Therefore PP inside, remaining visible, can beextracted. When DP is an external argument, on the other hand, Transfer applies when it moves toSPEC-T, rendering PP inside invisible. Subject island effects thus result. It will be shown in thepresentation that the relativized probing analysis can also account for cases where PP-extraction
from the subject is licit: when the subject is an internal argument and when the subject (an externalargument) undergoes successive-cyclic A-movement (Chomsky (2008)).
References: Baker, Mark C. (2011) “When Agreement is for Number and Gender but Not Person,” NaturalLanguage and Linguistic Theory 29, 875-915./ Bošković, Željko (1997) The Syntax of Nonfinite Complementation,MIT Press, Cambridge, MA./ Chomsky, Noam (2000)/(2001)/(2004)/(2007)/(2008)/(2012)/ Déchaine, Rose-Marie
and Martina Wiltschko (2002) “Decomposing Pronouns,” Linguistic Inquiry 33, 409-442.