46.
Chapter 2.
Taking the complement of V to be NP, (25) will be the general representation for a tensed clause such as that English is a language as well as for an untensed clause like for John to visit the hospital. The net result so far is a striking response to Plato"s problem. A large part of the computational system becomes operative just as minimal data trigger o the categorial and inflectional systems and determine one of the binary choices of the X-bar template; the child must seek this data in any case.
Some words of caution are needed here. First, no doubt, the brief sketch of X-bar theory was designed to show how this part of grammar solves Plato"s problem for the child by constructing a large chunk of grammatical organization when simple data for head orientation is made available to the child. This was not meant to show that the theory of parameters makes language learning trivial. After all, a grammar provides just an abstract format; it must be hooked on to the child"s experience and other cognitive resources. For example, the child needs to a.n.a.lyze even this simple data (drink milk) to figure out the syntactic properties of heads and complements from the rapid use of words in the linguistic environment.6 Not an easy task (Baker 2001, 213; Fisher, Church, and Chambers 2004). Fisher et al. (1994) present evidence that while children find it relatively easy to acquire sound-noun connections from environmental contexts alone, acquisition of verbs-even simple ones like go, do, push-seem to present insurmountable problems. Still, most interestingly, the corpus of verbs in caregiver speech directed at very young children frequently includes abstract verbs like think and want (Snedeker Gleitman 2004). Fisher and colleagues contend that verb learning requires considerable syntactic support. By ""syntax"" they basically mean argument structure with y-roles filled in (see below).
Second, I discussed only the head-orientation parameter because it is easy to understand (and relatively uncontroversial) to get the flavor of the rest of the machinery. Mark Baker"s meticulous work across a wide variety of typologically dierent languages suggests that up to six parameters need to be fixed to reach a specific language type. As Baker (2001) shows, sets of parameters branch out in regular ways to determine language types such that some language types may not have more than one common parameter. The set of parameters for a given language type form a hierarchy of increasing ""depth,"" suggesting an increasing degree of dif-ficulty for the child. With respect to Baker"s hierarchy, his review of research on language acquisition suggests that while the head-orientation parameter is fixed as early as twelve months, the fixing of the ""deepest""
might be delayed until the thirtieth month.
Linguistic Theory I
47.
Finally, I must mention that current research has already questioned some of the ideas sketched above. For example, Chomsky 1994a proposes a minimalist approach to X-bar theory leading to many modifications-in fact, a virtual abandonment-of X-bar theory; I discuss the new ideas later (section 5.1). In the current picture, the head parameter is not attached to the X-bar template since there is no such template. According to Chomsky 1995b, parameters are located in the morphological part of the lexicon, not in the computational system. More radically, there are proposals for a nonparametric conception of the faculty of language (Miyagawa 2006, cited in Chomsky 2006a).
From a very dierent direction, Richard Kayne (1994) proposes an elegant reformulation of phrase-structure theory from a single axiom, the Linear Correspondence Axiom (LCA), which states that ""syntactic structure is universally and without exception of the form S-H-C"" (specifier-head-complement) (Kayne 2004, 3).7 It follows, with wide support from crosslinguistic studies, that the distinction between head-last and head-initial languages may not be a primitive of syntactic theory. A closer look at syntactic heads across many languages suggests more fine-grained ""microstructures."" According to Jenkins (2004, xviii) the ""fine-grained study of language from the microparametric point of view might be compared to the study of the "fine-structure" of the gene which followed the earlier coa.r.s.er approaches of cla.s.sical genetics.""
2.3.1.3.
Theta Theory Apart from information about what they C-select, verbs also carry information, perhaps more obviously, about what they Sselect (""S"" for ""semantic""). Thus, looking back at the list of verbs with various C-selection properties, apart from saying that read C-selects an NP, it is natural to say that it S-selects a theme. (Perhaps it is more traditional to say that read S-selects an object. However, since object is also used for the functional categorial concept [NP, VP], I will use theme to avoid confusion. Sometimes I will also use object in an extended sense to include other complements such as [PP, VP] and [S0, VP] as well.) Extending the idea, we could say that hit S-selects a patient (who gets. .h.i.t), plan S-selects a goal, believe S-selects a proposition, persuade S-selects a theme and a proposition, and so on. With one exception to be noted below, these verbs will also S-select an agent of the given action where the agency will be a.s.signed to the element in the Subject position.
Notions such as theme, goal, patient, proposition, agent, and the like, which verbs S-select for, are collectively called ""thematic roles"" (y-roles).
These notions allow us to view verbs as predicate-argument structures 48
Chapter 2.
familiar from logical theory: y-roles are arguments that fill the relevant argument places in the matrix of a verb/predicate; similarly, for other lexical heads such as N, V, A, P, though I will keep to S-selectional properties of verbs only. If we include agency, then a sentence may be viewed as a predicate-argument structure as well. Clearly, there is a certain amount of redundancy between the C-selection and the S-selection systems; they basically establish head-complement relationships. In some places, Chomsky has suggested that the entire system of C-selection is possibly eliminable in favor of S-selection (Chomsky 1986, 8690). In other places, some doubts have been raised about the alleged redundancy from the point of view of language acquisition (Chomsky and Lasnik 1993, 1214).
For now, let us hold onto two indisputable facts: thematic relations are available to children as part of their lexical knowledge, and thematic structure is intimately related to the language module though possibly separate from it. We might as well try to make some use of these facts in grammatical theory, especially if they help solve some computational problems. As a step toward that end, let us ignore the conceptual aspects of the thematic structure by putting aside fine-grained conceptual distinctions between, say, themes, goals, recipients, patients, agents, experiencers, instruments, and the like, and work just with abstract y-roles. In other words, theoretically we need not care which role is a.s.signed to what argument as long as arguments are a.s.signed roles. However, I will continue to use notions of agent, theme, goal, and proposition for expository purposes. Let us a.s.sume that these notions ultimately get interpreted when the grammar interacts with the conceptual system; in grammar, I a.s.sume that abstract thematic roles just play computational roles. In doing this, I am indeed invoking thematic roles ""as a thinly disguised wild card to meet the exigencies of syntax"" (Jackendo 1990, 2.2).
Though it is part of lexical information that predicates S-select y-roles for various arguments, arguments cannot be lexically so marked since arguments are structural ent.i.ties. Thus y-roles need to be a.s.signed to designated arguments in a structure. Keeping to verbal predicates, the nature of a.s.signment may be displayed c.u.mulatively as follows (figure 2.4). The agent role is a.s.signed ""compositionally"" to the external argument by the phrasal node VP-while internal arguments are a.s.signed y-roles by the predicate itself. The figure shows which role is a.s.signed to which category of argument, although these details are not computationally relevant, as noted. It is obvious that internal y-role a.s.signment takes place under government.
Linguistic Theory I
49.
Figure 2.4 Y-role a.s.signment There is one universal exception to this system of a.s.signment: if V is a pa.s.sive participle-for example, kiss-en-then the external y-role is not a.s.signed; in other words, the pa.s.sive morphology en absorbs external y-role. This idea surely has a stipulative character though its eect is widely attested empirically (Lasnik and Uriagereka 2005, 126128). Also, there is a problem with data such as [John will kiss Mary], where the Infl will intervenes between the Subject John and the VP; this prevents the VP from a.s.signing the external y-role to John. This is one motivation for the VP-internal-Subject hypothesis (see below and Radford 1997).
With this system of a.s.signment in hand, a pending problem can now be addressed. Recall again that phrase-structure rules carried two sorts of information: categorial and configurational. We are still in the process of fixing the configurational part. X-bar theory, we saw, solves part of the problem by imposing a hierarchy on categorial elements along with the orientation parameter. C-selection, via the projection principle (29), links lexical properties with the X-bar template. We know that the (transitive) verb visit takes an NP complement, so the VP visit John is well formed; the expression satisfies C-selection and X-bar requirements along with the head-first choice for English. Note that C-selection and X-bar requirements are satisfied once at least one NP ""somewhere"" to the right of the verbal head becomes available. The restrictions do not say anything regarding (i) how many NPs at most are to be available to the right of visit, and (ii) where exactly to the right of visit these NPs are to be located.
Therefore, there is nothing in the requirements so far to prevent, say, *visit John an apple, which is not well formed; however, give John an apple is fine. Such facts are now easily explained via the thematic structure of verbs: an apple in *visit John an apple is not licensed since an apple is not a proper argument that visit S-selects for; give an apple to John is 50
Chapter 2.
well formed because give S-selects two y-roles, perhaps a recipient and a theme, a.s.signed here to John and an apple.
In general, then, y-a.s.signments may be used as a check on the enumeration of arguments in a structure in answer to (i) above; note that (ii) has not been answered yet. y-theory enables us to enumerate the arguments S-selected by the predicates in the sense that when each of the predicates has been inspected, the system knows exactly how many arguments are ""expected"" (Chomsky, Huybregts, and Riemsdijk 1982, 8689). It is natural to take the next step to formulate a preliminary criterion called ""y-criterion"" as follows; ""preliminary"" because it will soon be replaced by a more unified idea (in (33)) below.
(26) Every argument must be a.s.signed a y-role and every available y-role must be a.s.signed to an argument.
Notice that this criterion does not prevent a.s.signment of two y-roles to one argument. Consider John left the room angry. Here John gets a y-role compositionally from the VP left the room. Now compare this sentence with John made [Bill angry/leave], in which the Subject Bill of the ""small clause"" Bill leave must have a y-role that can only be a.s.signed by the predicate angry. So, by parity of a.s.signment, the predicate angry in John left the room angry a.s.signs a second y-role to John (Chomsky 1986, 91). Intuitively, it is John who (both) left the room and was angry.
Since (26) will ensure a tight fit between y-roles and arguments, (26) may now be viewed as a constraint that every subsequent syntactic structure must obey; in fact it is reasonable to think that y-theory was invoked essentially to enable us to formulate this criterion. In combination with the lexicon, and subject to constraint (26), the projection principle thus displays the complete predicate-argument information at d-structure; a d-structure may therefore be thought of essentially as a y-structure. In this display, there are positions that may possibly be occupied by arguments obeying (26). These are called ""argument positions,"" A-positions.
Nonargument positions are called A-bar positions; in particular, a Comp position is an A-bar position.
Since d-structure is now viewed as a projection of lexical information, important consequences follow. For example, ignoring details of hierarchy, (27) will be the d-structure representation of the pa.s.sive sentence Mary was kissed.
(27) e [Infl kiss-en Mary]
where en is the pa.s.sive marker that attaches to the verb (see Lasnik and Uriagereka 2005, 125128). Here kiss S-selects a theme that is a.s.signed Linguistic Theory I
51.
to the argument Mary, as required. In (27), however, the empty element e is projected due to a general principle (28), which we may call the ""Extended Projection Principle"" (EPP).
(28) Every clause must have a Subject.
The lexicon must therefore be viewed as containing a finite enumeration of empty elements to be projected onto syntactic structure as and when required. The presence of two projection principles might look inelegant.
So, it may be desirable to unify this principle with the projection principle (22) (Chomsky 1986, 116). Following developments in MP, the idea seems unnecessary. The projection principle is really needed for the intermediate syntactic structures such as d- and s-structures; it is trivially satisfied (or not) at the interface levels. Hence if the intermediate structures are not needed otherwise, as in MP, this principle will be infructuous. The Extended Projection Principle, however, continues to be a crucial constraint on well-formedness on independent grounds such as the existence of pleonastic Subjects in some languages such as English: there ensued a riot in Delhi, it rained heavily last night. I return to EPP in chapter 5.
Returning to (27), the Subject position is an A-position that is not a.s.signed any y-role due to the presence of a pa.s.sive marker in the a.s.signer (see the exception to figure 2.4). This allows the movement of Mary to the Subject position, leaving a new empty element, an NP-trace, behind. I return to the details of this movement after introducing Case theory. For the time being, notice that this movement gives a very natural explanation of why Mary, which is the theme/object of kiss, nevertheless occupies a Subject position in the pa.s.sive sentence; also, the movement is essentially triggered by the pa.s.sive morphology. We get the first glimpse of how dierent components of grammar interact to produce a grammatical ""action.""
2.3.2.
S-Structure Returning to the problem of ordering of elements, once the system has an enumeration of arguments licensed by criterion (26), an order may now be imposed on them if some principle that links arguments with the relevant positions in the structure is found. Now, an enumeration of all and only positions is already available from the general structure of a clause satisfying X-bar theory. So the ""relevant"" positions will be a proper sub-set of these positions; these can only be A-positions. Therefore, a principle that maps the set of arguments onto the set of available A-positions will finally solve the problem that arose with the elimination of phrase-structure rules.
52.
Chapter 2.
Thinking abstractly, it is clear that the principle is to be such as to identify some property of arguments that is not satisfied until a given argument occupies a designated position. In some cases, the principle will be automatically satisfied as soon as the argument is displayed at the d-structure. In other cases, the argument will move to a suitable (and licit) position to satisfy the principle causing another structure, s-structure, to form. Failing this, the argument cannot be licensed and the string in which it occurs will be rejected. So, by s-structure, all arguments must satisfy the principle; hence it is not relevant at the d-structure even though it may be satisfied at the d-structure.
2.3.2.1.
Case Theory The demand for such a principle is quickly met.
Case is a familiar grammatical property that is cla.s.sically linked to such functional notions as Subject and Object and is thus linked to designated positions in a structure. Thus, the Subject of a clause is said to have a nominative Case, the Object an accusative Case, the noun phrase of a PP an oblique Case, and so on. It is generally agreed that all languages have a Case system (Chomsky 1988, 101; Pinker 1995a, 115117), though the system is not overtly realized fully in most languages. Languages such as Latin and Sanskrit have a rich inflectional system in which varieties of Case are morphologically realized. English, on the other hand, is a Case-poor language in that Case is overtly realized only in p.r.o.nouns. Noting that only NPs have Cases and a.s.suming universality of at least a core Case system, we may temporarily adopt principle (29), called ""Case Filter.""
(29) Each phonetically realized NP must have Case.
Since Case is typically linked to functional notions, Case is also a.s.signed to various designated NPs as follows.
(30) a. Tense Infl a.s.signs nominative Case to [NP,S]
b. An active verb a.s.signs accusative Case to [NP,VP]
c. A preposition a.s.signs oblique Case to [NP,PP]
d. Genitive Case is a.s.signed without a.s.signer to possessives A special mention must be made of three categories that do not a.s.sign Case: (i) [N] categories-that is, nouns and adjectives-apparently do not a.s.sign Case (ii) Infl does not a.s.sign Case when it has the infinitival value to (iii) A pa.s.sive particle does not a.s.sign but absorbs Case Linguistic Theory I
53.
Each of these exceptions is controversial. Setting complications aside, (i)(iii) have far-reaching consequences. For example, (i) has the consequence that expressions such as the noun phrase translation [the book]
and adjectival phrase full [water] are correctly blocked. These expressions otherwise satisfy each of X-bar theory, C-selection, and S-selection. In English and in many other languages, these expressions require the insertion of a vacuous preposition of (translation of the book, full of water), which can now a.s.sign Case (Chomsky 1988, 110112).
Consequences of (ii) are particularly interesting. By the Extended Projection Principle, every clause, including an infinitival clause, must have a Subject. So, the VP to go home needs a Subject in order to be licensed.
Sometimes this Subject is an empty element called ""PRO,"" as in John wants [PRO to go home]. By (ii), PRO will not have Case but that will not violate principle (29) since PRO is not a phonetically realized element. We will see that other considerations imply that PRO has ""inher-ent"" Case.
English and some other Case-poor languages have an additional requirement that Case is a.s.signed to an adjacent NP-that is, nothing may intervene between an NP and its Case a.s.signer. Let us think of it as a parameter of the universal Case theory. Thus, we cannot have *put (on the table) (the gla.s.s) while put the gla.s.s on the table is permitted. When this condition is combined with the orientation parameter of X-bar theory, a rather strict word ordering (and hence, uniqueness of positions) follows for Englishlike languages. Adjacency requires that Case is a.s.signed to the complement that is immediately to the right or to the left of the head. English is a head-first language in that a complement is placed to the right of its head, so this position is uniquely designated for arguments to be licensed. The problem of configuration is thus finally solved. Languages that do not require Case adjacency will therefore have free word order to that extent (Baker 2001; Jackendo 2002 for extensive discussion).
Turning to (iii) and returning to (27) (e [Infl kiss-en Mary]), it is clear that the argument Mary is not licensed since it does not have Case (Rouveret and Vergnaud 1980), showing that a d-structure is not subject to the Case filter. Hence, Mary must move-raise-to the only A-position available, namely, the Subject position, which is currently occupied by an empty element. Since this position may be a.s.signed nominative Case, Mary gets the Case. We think of each movement as leaving a coindexed empty element-a ""trace"" of the vacated category-behind (Chomsky 1980, 146). Notice that movement vacates a category but does not eliminate it. Movement is essentially deletion and insertion. At the Object 54
Chapter 2.
position, Mary vacates the category NP where an empty element is inserted since the category continues to exist. At the Subject position, the movement deletes the existing empty element and Mary is inserted. The result is a new structure, an s-structure, roughly represented in (31).