Zero argument-structure-changing morphemes

My suggestion is in some ways akin to Pesetsky’s (1995) discussion o f zero morphemes. He assumes the existence of a repertoire of bound morphemes with null phonetic realisations, which have varying effects on the argument structure of those items to which they attach. Much of his discussion is based around CAUS, a zero morpheme that, when it attaches to certain verbs, has the property of introducing a thematic Causer to the predicate. Pesetsky assumes that such zero morphemes are derivational, contrary to my assumptions in section 3.2.2, but he also suggests that they are part of UG - that is, universally available, and only (parametrically) variant in terms of whether or not they are overtly realised. (CAUS is overtly realised in Japanese, for instance, but covert in English.) Further, Pesetsky suggests that features associated with CAUS may be strong or weak (a property of functional heads - Chomsky 1995a). I therefore maintain my assumption that argument-structure-changing affixes, phonetically

null or not, are part of the UG lexicon and as such, functional in nature.

Pesetsky’s zero morphemes have various effects on the argument structure of the predicates to which they are affixed. CAUS, for instance, can introduce a Causer role and / or suppress the external theta role of a verb. If some such process has been applied to unaccusatives, Pesetsky points out, this would account for the often observed fact that unaccusatives cannot generally be passivised (see (11) - (14)):

(11) a. The train disappeared over the horizon.

b. *The horizon was disappeared over (by the train).

(12) a. The shrub wilted in the poor soil.

b. *The poor soil was wilted in (by the shrub).

(13) a. The students arrived in the examination hall.

b. *The examination hall was arrived in (by the students).

(14) a. John trembled under the stem gaze of the magistrate.

b. *The stem gaze of the magistrate was trembled under (by John).

The extemal argument of an unaccusative has already been absorbed by affixation of some abstract morpheme, leaving no Agent role to be assigned to the passive morphology. This would lead to a violation of the theta criterion, because effectively the passive morpheme is an argument, so must receive a theta role (cf. Baker, Johnson and Roberts (1989), and Jaeggli (1986)).

In the spirit of Pesetsky’s analysis, I propose that there is a functional head, UNACC, with a null phonetic realisation, to which verbs may be adjoined in the morphological component, and which, like Pesetsky’s CAUS, absorbs an extemal argument:

(15) UNACC

UNACC may be akin to the passive morpheme PASS, which has the property of existentially binding the extemal argument of an underlyingly transitive verb, so that it is realised syntactically as a passive; however, there is evidence that MC treats passives as affixed verbs, not as if they are headed by a functional morpheme. It may be, then, that UNACC and PASS are similar to each other in that they have effects on argument structure of verbs without inducing category changes, but that they are dissimilar from each other in their lexically stated requirements to be affixed to a substantive or to have one adjoined to them. (Note that my suggestion for the underlying realisation of unaccusatives, which results from adjunction of a substantive to a functional morpheme at the level of the morphological component, is tantamount to the assumption that unaccusatives are functional heads by the time they enter the syntactic component.) Note that UNACC is also likely to be akin to CAUS, the morpheme assumed to trigger causativisation. W e have already seen that it is difficult to passivise an unaccusative, or to assign one a causative reading; these observations are readily accounted for on the assumption that CAUS, UNACC and PASS are morphemes which are all associated only with transitive verbs. Once one of these morphemes has been affixed or adjoined to a verb, its argument structure is altered and it no longer fulfils the requirements which would permit it to become associated with another of these morphemes. The possible repertoire of zero morphemes is discussed further in section 3.4.3 below.

Returning for now to the case of unaccusatives, it could be assumed that an unaccusative has an underlying (lexical) structural representation which is the same as that for a transitive verb, with positions for internal and extemal arguments. But V which has an obligatory unaccusative realisation has some ‘diacritic’ associated with its lexical entry, which means it must be adjoined to UNACC before entering the syntactic derivation.

To clarify, the (pre-syntactic) derivation of an unaccusative verb would follow several steps, as illustrated in (16) below:

(16) a. Vunacc (underlying lexical representation)

b. VP

external argument V

V intemal argument

UNACC + V (following adjunction of V to UNACC)

Argument stmcture: [2] (intemal argument only is selected for; extemal 0-role has been absorbed by adjunction to UNACC)

UNACC P

UNACC

UNACC intemal argument (extemal 0-role absorbed by UNACC; intemal theta role is assigned to complement of UNACC, to which V is adjoined)

I assume that, when it enters the derivation, UNACC has no specifier position because neither Case nor a theta role are to be assigned to anything in subject position. The derived subject (if there is one; recall that we are considering the syntax of single words here) would be Merged as the complement of UNACC, where it receives the intemal theta role, and would then move (as per standard assumptions) to Spec, IP to check (nominative) Case. (16d), then, shows the intemal (morphological) stmcture of an unaccusative verb as it enters the syntactic component.