Uninterpretability is incompatible (in morphology) with other minimalist postulates.
Consequences for Agree and Move.
1.
The nature of morphology. Much work in generative morphology supports the conclusion
that syntax and morphology share some significant principles of structural organization, for instance
a rule forming headed constituents (Williams 1979). In the model of the Latin verb by Embick and
Halle (forthcoming), schematized in (1), the morphological categories of aspect and tense as well as
the hierarchies they enter into have an exact parallel in the syntax, as schematized in (2); thus
common (computational and interpretive) principles must underlie both. Given the extent of the
overlapping, we take it that optimally there should be a single morpho-syntactic component,
submitted to all and only the same principles.
(1)
[T [Asp [v laud-a] v-e] r-a] mus
(2)
Subj [TP T [AspP Asp [vP v VP]]]
2.
The agreement morphology of the verb.
If we were to reason on the basis of results such
as those in (1)-(2), it would be natural to suppose that the agreement inflection of the verb (-mus in
(1)) furthers the parallelism with the sentence, lexicalizing the same category in the morphology as
the subject in the syntax. However in the minimalist model of Chomsky (1995, 2000, 2001), it is
axiomatic that the agreement morphology of the verb corresponds to an uninterpretable set of
features. Thus the agreement features of the verb cannot correspond to a syntactically merged
category, but must be valued in the course of the derivation (setting it in motion, as a matter of fact)
and then eliminated from the syntax. Accordingly, Embick and Halle (forthcoming) assume that the
agreement inflection of the Latin verb is merged not in the (morpho-)syntax as the other categories
in (1), but rather in a specialized morphological component. The first price to pay for this analysis
is the existence of the morphological readjustment component itself, hence the impossibility of a
completely unified morpho-syntax, as well as the potential availability in the morphology of a series
of mechanisms forbidden by the restrictive principles of syntax. The second price, itself a
consequence of morphological readjustment, is Late Insertion, which runs counter the minimalist
core idea that all syntactic structure is projected by lexical material (essentially the principle of
Inclusiveness).
3.
Empirical evidence regarding the agreement morphology of the verb.
The
theoretical
argument against the treatment of verbal agreement via morphological readjustment is strengthened
by the available empirical evidence. In particular we argue that there is evidence in favor of a
treatment of the agreement inflection as a verb-internal pronominal subject. Thus consider Romance
languages with subject clitics, i. e. Northern Italian dialects (and arguably Romantsch dialects,
French); identical lexicalizations of the subject clitic and of the corresponding verb morphology
include at least (3).
(3)
1 sg: i
e.g. i dorm-i ‘I sleep-1sg’ (La Pli de Mareo, Alto Adige)
2 sg: t
e.g. te mangia-et ‘you ate-2sg’ (Strozza Valle Imagna, Lombardy)
1 pl: n(e) e.g. mangiau-ne ‘ate-1pl’, ne llavamu ‘ourselves wash’ (Giurdignano,Apulia)
2 pl: v
e.g. vi lavava-vu ‘yourself washed-2pl’ (Camporeale, Sicily)
3 pl: n
e.g. in l a-n ciamau ‘they him have-3pl called’ (Airole, Liguria)
Furthermore, so-called agreement inflections of the verb can be interleaved in the
pronominal clitic series, notably in the plural imperative, both in Romance and in Albanian dialects.
(4)
a.
da-me-te-lle 



(Albidona, Calabria)
give-me-2pl-it (‘Give it do me!’)
b.
o-m-ni-e
(arberesh, Carfizzi, Calabria)
give-me-2pl-it (‘Give it to me!’)
Evidence similar to (4) is known to Halle and Marantz (1994) from Caribbean Spanish.
Their treatment, consistent with the model of minimalist syntax/Distributed Morphology, involves a
syntactic structure where the agreeing verbal form is followed by an enclitic group, and a
morphological readjustment rule infixing the clitic group betwen the verb stem and its inflection.
But consider the fact that the phenomenon in (4) is restricted to imperatives. It is a widely held
theory that the imperative occupies a very high position in the sentence (Rivero 1994), say a high C
position in a Rizzi (1997)-type hierarchy. This high position of the imperative can be argued to
leave the syntactic space necessary for the stranding of the agreement inflection, effectively a
subject clitic, and hence the space necessary for the appearence of enclitics both to the verb stem
and to its inflection, roughly within the dotted lines in (5). Note that the verb stem corresponds to
the 2 person singular imperative and can therefore independently lexicalize the Cn position.
(5)
[Cn imperative stem … [imperative inflection …
In our presentation we shall work out the syntactic account in (5) in full detail. What is
immediately relevant is that the alternative morphological account would need to stipulate a number
of properties that already follow from the syntax as part of the morphology. Thus there is no
morphology-internal reason why the agreement inflection of the verb should be splittable from the
stem, to the exclusion for instance of the modal inflection of the infinitive -- which in Southern
Italian dialects of the type of (4a) equally involves enclisis. Similarly, there is no reason why a
morphological rule that has the power of infixing (part of) an enclitic group shouldn’t have the
power of infixing (part of) a proclitic group. A further line of argument can be developed starting
with the observation that the split between clitics always has 1 and 2 person clitics infixed and 3
person ones as enclitics. The dissociation between 1/2 and 3 is independently known in the syntax
(where it underlies split ergativity and more) and understandable in interpretive terms as a
dissociation between discourse- and event- anchored arguments. But in the morphology such a split
can only be stipulated. In short, a treatment of the agreement inflection of the verb as as a
pronominal subject inside the verbal structure is best suited to explain the evidence in (3)-(4); in this
respect as well, we uphold the unification of morpho-syntax.
4.
Potential problems for our argument.
Before coming back to the consequences of our
conclusions for the minimalist model, we review (as time allows) some more specific, morphologyrelated potential objections. Embick and Halle (forthcoming) treat so-called tematic vowels in terms
of morphological insertion as well -- these are the vowels (hyphenated in (1)) that close off the
consonantal verbal root as well as the tense and aspect morphemes. The model envisaged here
commits us to an interpretable treatment of thematic vowels as well. Thus we know that the verbal
root augmented by the thematic vowel enters into nominal compounds in Romance languages
(French tire-bouchon, Italian cava-tappi ‘cork screw’). On such evidence (and other) we take it that
thematic vowels are nominal morphology, representing essentially the internal argument.
Another objection to which we lie open is that something like morphological readjustment
and Late Insertion is independently needed. One reason for Late Insertion is ‘syncretism’, i.e. the
fact that one and the same piece of morphology can lexicalize several different bundles of features.
In this respect we take the line of Manzini and Savoia (2002, 2004), who consider such phenomena
in the clitic system of several Romance dialects. Thus ‘syncretism’ between the (masculine) plural
and the ‘dative' is the byproduct of a common quantificational features, that allows for both the
plural interpretation and the distributor (dative) one. Analogously the ‘syncretism’ between dative
and locative issues from the fact that the ‘dative’ can be equally lexicalized as a directional. In a
nutshell, there is no abstract underlying ‘dative’ feature, therefore there is no ‘syncretism’, but
simply a different range of interpretation of quantificational, locative categories (and more), which
parametrically includes the distributor, directional (etc.) argument of certain events.
5.
Agree and Move. Let us then return to the conclusion that the finite agreement of the verb
corresponds to an interpretable morpho-syntactic category, as a pronominal subject does. The
obvious consequence is that the agreement of such a category with a lexical subject cannot be
treated in terms of minimalist Agree. Now, generative grammars typically allow for a different
Agree, whereby the agreement between two nominal categories both introduced by Merge, allows
for their coreference. This interpretive construal of Agree, independently needed for
pronominalization, can be extended to subject-verb agreement. To the extent that Agree is a
subcomponent of Move (up to Chomsky 2001:23), the computational construal of Move itself is
then called into question, and an interpretive construal (Brody 1999) potentially favored.