6    Subject movement and case theory

A first look at case

(1)	a.	ok	They will help her.
	b.	ok	She will help them.
(2)	a.	*	Them will help she.
	b.	*	Her will help they.

Why are the sentences in (2) ungrammatical? The answer is that the grammar of English requires subjects and objects to appear in a specific case form. In general, subjects appear in the nominative (with an exception to be discussed later on), and objects appear in the oblique. The nominative and oblique forms of English ordinary pronouns are shown in (3) (see Glossary for abbreviations and further information on ordinary pronouns).

(3)				Nominative		Oblique
			1 sg		I		me
			2 sg/pl		you		you	<<<
			3 sg m		he		him
			3 sg f		she		her
			3 sg n		it		it	<<<
			1 pl		we		us
			3 pl		they		them

As is evident, both of the subjects in (2) are oblique forms, and both of the objects are nominative forms. Each of the sentences in (2) therefore contradicts the case requirement just stated in two ways.

Morphological case

As the leftward-pointing arrows in the table in (3) indicate, not all pronouns have distinct forms for the nominative and the oblique case. Full noun phrases in English also show no morphological distinction between nominative and oblique forms, as shown in (4).

(4)	a.	ok	The neighbors will help my friend.
	b.	ok	My friend will help the neighbors.

Of particular interest in this context are the case forms of the interrogative pronoun who. In older forms of English, the nominative was (the precursor of) who, and the oblique was (the precursor of) whom. The schools more or less valiantly attempt to uphold this distinction, but for most contemporary speakers of English, whom is dead as a doornail, at least as a syntactically conditioned oblique case form. To the extent that whom still occurs in the written language, it appears to have been reinterpreted as a stylistically conditioned formal variant of who. That is, speakers appear to be following a rule that says "Say whom when you want to sound educated" rather than a rule that says "Say whom when it is the object of a verb". Some examples of this hypercorrect use of whom are given in (5).

(5)	a.		As soon as he reached the trees a party of hunters, whom the man knew would be there, caught him. (cf. hunters who/*whom would be there) (Idries Shah. 1968. Caravan of dreams. Octagon Press. 93.)
	b.		I've been stashing away the lists as they come up, for whomever that reviser may be. (cf. Who/*Whom will that reviser be?) (hfleming@sas.upenn.edu to germ-all@ccat.sas.upenn.edu, 1 October 1998.)
	c.		The rare reports of people meeting others whom they did not know had died … (cf. others who/*whom had died) (Eugene d'Aquili and Andrew B. Newberg. 1999. The mystical mind. Probing the biology of religious experience. Fortress Press. 140.)
	d.		… it is our responsibility to do what we can to identify in advance students whom we seriously suspect may not be able to cope with the academic expectations and/or emotional pressures of an extended foreign study experience. (cf. students who/*whom may not be able to cope) (Penn Abroad Application 1999)
	e.		The Democrats in Connecticut are all set to run a popular candidate, state Attorney General Richard Blumenthal, whom everyone agrees would win the seat. (cf. Who/*Whom would win the seat? ) (http://www.michaelmoore.com/2000_10_20.html; accessed 30 October 2000.)
	f.		Republicans and Democrats react to whomever has the upper hand. (cf. Who/*Whom has the upper hand?) (http://www.salon.com/politics/feature/2000/11/15/nader/index1.html; accessed 14 November 2000.)
	g.		They were dependent on me, or whomever was their caretaker was for the day, to water, to keep them moist. (cf. Who/*Whom was their caretaker for the day?) (Pamela Bloom. 2000. Buddhist acts of compassion. Conari Press. 45.)
	h.		Take small gifts, such as flowers or cookies, and give them to the people whom you think can help you the most, to show your appreciation. (cf. the people who/*whom can help you the most) (Jeff Davidson. 1999. The joy of simple living. Emmaus, PA: Rodale Press. 333.)

Besides failing to express its case distinctions in a robust manner, English also exhibits a comparatively limited range of case forms: the nominative and the oblique just discussed, and the possessive. Other languages have more grammatical cases. For instance, instead of a single oblique case, German has a dative and an accusative, giving it four cases in all (nominative, genitive, dative, accusative). As in English, the nominative marks subjects of sentences, and the German genitive corresponds closely to the English possessive. With ditransitive verbs, the first object (the beneficiary or recipient) appears in the dative, and the second object in the accusative, as shown in (6). (In this and following examples, relevant inflectional material is underlined.)

(6)	a.		deinen Eltern	einen Brief	schicken
			your parents.dat	a letter.acc	send
			'to send your parents a letter'
	b.	*	deine Eltern	einem Brief	schicken
			your parents.acc	a letter.dat	send
	c.	*	deinen Eltern	einem Brief	schicken
			your parents.dat	a letter.dat	send
	d.	*	deine Eltern	einen Brief	schicken
			your parents.acc	a letter.acc	send

With simple transitive verbs, the situation is more complex. Such verbs are said to govern the case of their object. That is, depending on the verb, the object appears in the accusative, in the dative, or (rarely) in the genitive. For all practical purposes, the case that a particular verb governs is not predictable and must be learned by rote, since even verbs with similar meanings may govern different cases, as (7) and (8) illustrate.

(7)	a.		dem Kind	{	helfen,	nachlaufen	}
			the child.dat		help	run after
			'to help, run after the child'
	b.	*	das Kind	{	helfen,	nachlaufen	}
			the child.acc		help	run after

(8)	a.		das Kind	{	unterstützen,	verfolgen	}
			the child.acc		support	pursue
			'to support, pursue the child'
	b.	*	dem Kind	{	unterstützen,	verfolgen	}
			the child.dat		support	pursue

Prepositions, too, idiosyncratically govern the dative, the accusative, or (rarely) the genitive. Several German prepositions can govern both the dative and the accusative, in which case the dative marks location, whereas the accusative marks direction.

(9)	a.	Location:		in	{	der Bibliothek	/ *	die Bibliothek	}	arbeiten
				in		the library.dat		the library.acc		work
				'to work in the library'
	b.	Direction:		in	{	die Bibliothek	/ *	der Bibliothek	}	schicken
				in(to)		the library.acc		the library.dat		send
				'to send (in)to the library'

A four-case system like the one just described for German was found in Old English (700–1150), but the distinction between the dative and the accusative was lost during the Middle English period (1150–1500), leaving the modern language with only a single oblique case. Also in the course of the history of English, the genitive developed into the possessive.

Some languages have even more cases than the ones just described. Finnish has been argued to have over a dozen productive cases, and Turkish has six: nominative, genitive, dative, accusative, locative (for locations), and ablative (used to mark the origin or source of movement). Proto-Indo-European, the reconstructed ancestor of the Indo-European language family, had eight cases: the ones just listed for Turkish (which does not itself belong to the Indo-European family), along with an instrumental (for instruments and means) and a vocative (used to address someone by name). The original Indo-European case system is best preserved in the Baltic languages (Latvian and Lithuanian) and in many Slavic languages, including Ukrainian and Czech. In these languages, the ablative merged with the genitive, leaving seven cases. Several other Slavic languages, including Russian, have almost completely lost the vocative, leaving only six cases (nominative, genitive, dative, accusative, locative, instrumental). In Latin, the Proto-Indo-European ablative, instrumental, and locative merged into a single ablative case that serves all three functions. In Ancient Greek, all three of these cases were lost, but the vocative survived, leaving five cases (the four cases discussed for German and the vocative).

There are also languages with even weaker case systems than English. For instance, the Romance languages distinguish nominative and oblique only on pronouns, but in contrast to English, they have no possessive. Finally, some languages, like Chinese, lack morphological case entirely.

Case features

(10)	a.		They will help her.
	b.		She will help them.
(11)	a.		You will help her.
	b.		She will help you.

As is evident, they and she exhibit distinct forms in the nominative and oblique, whereas you doesn't. But in generative grammar, the focus is not on this morphological difference, but instead on the fact that the form you appears in the same structural position as they and she in (11a), but as them and her in (11b). Contrary to superficial appearances, the two instances of you in (11) are therefore treated not as tokens of a single type, but rather as two grammatically distinct forms that happen to be homonymous.

In order to disambiguate between such homonymous forms and also, more generally, in order to describe the distribution of case forms, it is useful to postulate case features, whose values range over the various cases that a language exhibits. The case features represent abstract case, which may, but need not, be overtly expressed as morphological case, as we just saw in (10) and (11). We will further assume that case features are assigned by heads to noun phrases. That is, we can think of them as originating on heads, and then being transmitted from those heads to noun phrases under certain structural conditions. At the end of the derivation of a sentence, no case feature may remain on the head it originated on, and every noun phrase must be associated with a case feature. The latter requirement is often referred to as the case filter. Given these assumptions, the aims of case theory include specifying which heads in a language bear which case features, and under what structural conditions case features can be transmitted from heads to noun phrases.

Case features are sometimes said to be checked rather than transmitted. The idea is that noun phrases have case features from the very start of a derivation, and that each case feature on a noun phrase must be checked off against a corresponding case feature on a head, subject to appropriate structural conditions. In this chapter, we adopt the case assignment perspective over the checking perspective for expository reasons.

Licensing configurations

(12)			A governs B iff
			a.	A is a head,
			b.	B is a maximal projection, and
			c.	A and B are sisters (= mutually c-command each other).

In English, oblique case is a feature associated with V and P, and oblique case is therefore assigned to sisters of V and P.

Specifier-head agreement

In English, it is therefore generally assumed that elements sharing a nominative case feature must be related as specifier to head. This relation is standardly referred to as spec(ifier)-head agreement. Subject movement is then a straightforward consequence of this assumption. Since Spec(IP) is conveniently empty in structures like (14), nothing stops the subject from moving and being assigned nominative case there.

Mediated case assignment

(17)

I was expecting (that) she would dislike him.

The semantic parallel between (16) and (17) strongly suggests that the complement of expect in (16) is the entire sequence her to dislike him. Specifically, it suggests that to in (16) is the counterpart of would in (17). This yields an underlying (= initial) structure for (16) as in (18a). Subject movement of the matrix and complement subjects then yields the structure in (18b).

(18)	a.				b.
			Before subject movement				After subject movement

The analysis in (16) is further supported by an empirical argument based on the distribution of so-called expletive there. Expletive there differs from ordinary adverbial there in being unable to bear stress. The contrast in (19) suggests that expletive there is restricted to subject position and unable to function as the object of a verb.

(19)	a.	ok	There is a fly in my soup.
	b.	*	I dislike there in my soup.

Now it was noticed early on in generative grammar that there is a contrast in examples like (20).

(20)	a.	*	I was expecting there.
	b.	ok	I was expecting there to be trouble.

The contrast in (20) would be mysterious if there were a complement of expecting in both examples. But the mystery dissolves if there is the subject of an IP in (20b), just as it is in the paraphrase of (20b) in (21).

(21)

I was expecting (that) there would be trouble.

The question of course remains of how the complement subject in (18b) can receive oblique case from expecting, given that it is not itself the verb's complement. In order to answer this question, let us be clear about the goal of case assignment, which is to transmit a case feature from a case assigner to a noun phrase. In the instances of case assignment discussed so far, this transmission is direct (that is, it proceeds in a single step). But in a configuration like (18b), the best the verb can do is to transmit its oblique case feature to IP under government. But the case features are useless on IP, since case can only be realized on noun phrases.

Let us therefore introduce two modifications concerning how case features are transmitted in a tree. First, let us say that case features are transmitted not simply to a maximal projection, but to the entire spine of the projection under consideration. Imagine clones of the case feature being smeared along the entire spine. So in the case at hand, the verb expecting assigns its oblique case feature under government to its sister IP, and then the case feature is cloned along the spine of the IP. This means that the complement I' and I now bear the oblique case feature too. Second, let us now allow I to transmit the oblique case feature to its specifier under spec-head agreement. We can think of this second step as a last resort measure that allows the verb's case feature to be transmitted to a noun phrase that would otherwise remain without a case feature.

The two-step process just described is often referred to as exceptional case marking (ECM). One aspect of it that is undeniably exceptional is that it assigns oblique case to subjects, which generally receive nominative case. This means that subjects of clauses cannot be defined as noun phrases that are assigned nominative case. A simple alternative definition is available, however—we can simply say that subjects of clauses are the noun phrases that occupy Spec(IP). But ECM is not completely exceptional, since it involves both of the structural configurations introduced earlier—government and spec-head agreement. In order to highlight this aspect of it, we will generally refer to it instead as mediated case assignment. As mentioned earlier, in ordinary case assignment, a case feature is transmitted from a case assigner to that case assigner's complement or specifier in a single step. Mediated case assignment, on the other hand, requires a mediating head in addition to the original case-assigning head. In the case just discussed, the original case-assigning head is the V of the matrix clause, and the mediating head is the I of the complement clause.