Government and Binding Theory/A-Movements

Finally, with the basics of theta theory learnt, we can commence our treatment of movements in the GB framework! Let us begin by examining the sentences we looked at back in our introductory book. We had three sets of sentences:

(1a) It seems that Wikibooks is useful. (1b) Wikibooks seems to be useful. (2a) You will try to steal what? (2b) What will you try to steal? (3a) Volunteers wrote the Linguistics textbook. (3b) The Linguistics textbook was written by volunteers.

There is a common denominator among the first and the third, one that you might have noticed back then (which probably feels like eons ago by now.)

The common denominator between these three is that they both involve raising a DP – respectively, Wikibooks and the Linguistics textbook – to subject position. This type of movement is called the A-movement (or NP movement). Firstly, though, we need to look at the important principles that guide movement.

UTAH
No, UTAH is not the US state. It's the Uniformity of Theta Assignment Hypothesis (UTAH):

If two arguments in have the same θ-role in S-structure, then they must have been generated in the same position at D-structure.

Let's use (3a) and (3b) as examples. Volunteers is the agent and the Linguistics textbook is the patient in both sentences. We can thus conclude that they were generated in the same place at D-structure.

Structural Preservation Principle
X-bar structures cannot be altered by movement.

This may sound counter-intuitive, since we're transforming a D-structure into an S-structure. There are a few implications we can derive from this:


 * We cannot add new phrases, projections or other structures when we move constituents around.
 * We cannot change them: IPs remain IPs, V′s remain V′s and so on.
 * In movement, what we are doing is to move a constituent from its original location to an unoccupied location. We might, for example, move something from the head position of XP to the unoccupied head position of YP.

Forget about the syntax trees regarding movement that we met in our introductory book. They have no place here.

Since we've learnt these principles now, let us see them in action.

A-Movements
We will discuss three types of A-movements because they are common in English.

The Passive
Let's use our (3a), deleting by volunteers for simplicity's sake:

(3c) D-structure of (3b):           &mdash;             was written the Linguistics textbook (3d) S-structure of (3b): The Linguistics textbook was written          &mdash;

Structurally:
 * The active object starts its life in the passive D-structure as an object.
 * The θ-role, patient in this case, is assigned to the object.
 * It is moved to the unoccupied specifier position of the IP to become the subject, with the θ-role retained.

We can also represent this diagrammatically:

⇒

Raising
Before we talk about raising, we need to take note of a category of predicates that only takes an object. Consider:

seem [__ CP[+fin]]&lt;theme&gt; appear [__ (CP[+fin])]&lt;theme&gt; likely [__ (CP[+fin])]&lt;theme&gt; possible [__ (CP[+fin])]&lt;theme&gt;

Note that likely is also a predicate as it is the one expressing a state, not the be that precedes it. As they do not take subjects, we need a pleonastic subject in its place to satisfy the Extended Projection Principle:

(4a) It appears that I have done my homework. (4b) It is likely that I have done my homework. (4c) It is possible that I have done my homework.

However, it seems that for some of these verbs, the pleonastic subject are able to be eliminated by movement (or, rather, the pleonastic subjects of some of these verbs seem to be able to be eliminated by movement):

(5a) I appear to have done my homework. (5b) I am likely to have done my homework. (5c) *I am possible to have done my homework.

This is known as raising and it is another type of A-movement. Consider:

(6a) D-structure of (5a):   &mdash;    appear I to have done my homework (6b) S-structure of (6a):   I    appear &mdash; to have done my homework

We can note the following points about this type of movement:
 * The subject of the CP in the original constructions starts life as the subject of the non-finite clause, and is assigned a θ-role by its predicate.
 * The subject then moves to the specifier position of the IP.

⇒ ⇒

Ergative verbs
An ergative verb allows the subject to be omitted and the object to be moved to the subject position, a phenomenon sometimes called the middle voice. Consider:

(7a) I broke the windows. (7b) The windows broke.

We can model this phenomenon as an A-Movement as well:

(7a)     &mdash;      broke the windows (7b) The windows broke     &mdash;

We note that the situation is similar to the passive:
 * The active object starts life in the object position. Its θ-role is assigned by the predicate.
 * The active object moves to the subject position.

Let's also map this diagrammatically:

⇒

A-movements are everywhere
In the diagrams above, we have deliberately missed out one important part of the puzzle: The specifier of the VP. Recall, from last chapter, that the subject originates in the VP according to the VP-internal subject hypothesis. Thus in our above cases, the subject actually jumps to the specifier position of the VP before proceeding to the specifier position of the IP. Thus A-movement occurs in practically every sentence.

Defining A-movements
Note that so far, all of our movements deal with DPs that have been assigned θ-roles, not just any DPs. We cannot move adjunct DPs:

(9a) Colourless green ideas sleep furiously all day long. (9b) *All day long sleep furiously.

Note that although all day long may have a semantic role in our regular definition, it lacks a θ-role in GB theory.

This leads us to our definition of A-movements:

An argument with a θ-role is moved to the subject position.

Yet we know that DPs aren't the only elements that move - adjuncts, for example, are perfectly capable of moving. What happens then?