one of the thematic or theta-roles, where the argument deliberately performs an action, as Jamie in Jamie sang a song or Robert in Robert kicked the cat. In terms of the UTAH the agentive theta-role is assigned to the specifier position of vP, similarly to experiencer arguments.


a structure is ambiguous if it can be interpreted in more than one way. We differentiate lexical ambiguity from structural ambiguity.


the participants minimally involved in an action defined by the predicate. The complements and the subject, the latter also called an external argument.


a structure containing a (visible or invisible) subject and a predicate.

ergative language

a language where the subject of an intransitive verb and the object of a transitive verb have the same Case form.

ergative verb

a verb that can appear in a VP either (a) with a single theme argument functioning as the subject of the clause (The ship sank), similarly to unaccusative structures or (b) in the presence of a light verb together with an agentive subject (They sank the ship), when the structure is similar to the structure of transitive verbs. As opposed to unaccusative verbs, ergative verbs cannot appear in the existential there construction (unless they are ambiguous between the two readings), and they are typically verbs expressing a change of state, like break, explode, grow.

event structure

verbs can express simple or complex events. Event structure describes what sub-events an event expressed by a certain verb is made up of. This has an effect on the syntactic organisation of elements within the VP. There is supposed to be an isomorphism between event structure and the structure of the VP: a VP breaks up into sub-vPs/VPs in a one-to-one correspondence with the sub-events.

intransitive verb

a verb without a nominal complement (the object), e.g. ski. Its subject is either an agent or an experiencer, i.e. one of the theta-roles assigned to the specifier of a vP. Occasionally intransitive verbs appear with a cognate object.


a one-to-one correspondence between the members of two sets.


a system that enables people who speak it to produce and understand linguistic expressions.

light verb

a verb occupying the head of a vP used in combination with another element, typically a noun or verb, where the light verb’s contribution to the meaning of the whole construction is less than that of a fully thematic main verb, e.g. to take a shower=to shower. Certain verbs expressing aspectual (be, have) or modal (let) meaning also belong here. According to the proposals in the present book the following constituents can appear within the vP in a visible or abstract form (see also vP-shells):

– agentive arguments in the specifier positions

– experiencer arguments in the specifier position

– goal arguments in the double-object construction as specifiers

– the passive -en morpheme in the head of vP

– the aspectual morphemes -en and -ing in the head of vP

– the tense morpheme in the head of vP

locative inversion

a structure where a PP locative argument apparently sits in subject position while the DP theme sits behind the verb, as in In the corner sat a shadowy figure.


a DP complement immediately following the verb. It can move to the subject position in passive sentences. See also direct object, indirect object.

specifier position

a position defined by X-bar Theory. The specifier is sister to X', daughter of XP. It is a phrasal position, the nature of the phrase depends on what it is the specifier of. E.g. the specifier of IP is the subject, the specifier of DP is the possessor in possessive structures.


one of the thematic roles where the argument is not affected by the action described by the verb e.g. in Peter saw John nothing directly happens to John as a result of being seen. In terms of the UTAH the theme theta-role is assigned to the specifier position of the VP.

there-construction: see existential there-construction.

theta role

the semantic role of the participants as required by the predicate. E.g. verbs define what kind of semantic relationship is to be established between the verb itself and the arguments of the verb, and arguments are selected accordingly. The verb kick calls for an agent subject, so its subject position cannot be occupied by e.g. my CD-player.

transitive verb

a verb with a nominal complement, e.g. read, buy. The agentive subject occupies the specifier position of vP, the theme object occupies the specifier position of VP.

unaccusative verb

a verb taking one argument to which it assigns a theme theta-role in the specifier position of a VP. They may also optionally take a location or path argument expressed by a PP. Some of the unaccusative verbs in English are arrive, appear, sit, they are typically verbs of movement or location. Unaccusative verbs can appear in the existential there construction or locative inversion structures. They do not take objects of any kind, see also cognate object.

Uniform Theta-role Assignment Hypothesis (UTAH)

a Θ-role is assigned in the same structural position in all structures in which it is present.

Basic English Syntax with Exercises

5.2.3 Ergative verbs

We have just seen that a verb like break can appear in a VP with a single theme argument which in the absence of a light verb will be the subject of the clause. This looks exactly like an unaccusative verb, yet there are differences between this class of verb and the unaccusatives. For one thing, these verbs are not movement or locative verbs, but typically involve a change of state:

(34)athe window broke
bthe door closed
cthe glass shattered
dthe ship sank
ethe bomb exploded
fthe tree grew

Furthermore, these verbs do not appear in there sentences or locative inversion structures:

(35)a*there broke a window
b*there sank a ship
(36)a*in the house opened a door
b*in the cupboard shattered a glass

Apparent exceptions to these observations may again be accounted for by assuming an ambiguous status of the verb involved. For example, the verb grow can apparently behave like an unaccusative:

(37)athere grew a tree in the garden
bin the garden grew a tree

In these examples, however, it might be that the verb has a locative interpretation rather than a change of state interpretation. If we force the change of state interpretation, the verb ceases to behave like an unaccusative:

(38)athe tree grew bigger
b*there grew a tree bigger
c*in the garden grew a tree bigger

Another major difference between this group of verbs and unaccusatives is that this group can apparently appear in a transitive context:

(39)aI broke the window
bshe closed the door
che shattered the glass
dthey sank the ship
ethe police exploded the bomb
fthe gardener grew the tree

Most unaccusatives cannot appear transitively:

(40)a*he arrived the letter
b*they departed the train
c*the magician appeared a rabbit
d*the Romans lived the Picts in Scotland

Some can, however:

(41)awe sat the guests at the table
bhe stood the ladder against the wall
cthe rats spread the disease
dthey ran a pipeline under the sea

In these cases, these verbs are unable to appear in there or locative inversion structures and so again this may be another case of ambiguity:

(42)a*there sat the host some guests at the table
b*there spread the rats a disease
(43)a*against the wall stood the builder a ladder
b*under the sea ran the engineers a pipeline

These verbs that have a transitive and an unaccusative use are sometimes called ergative verbs as the subject of the unaccusative version is interpreted the same as the object of the transitive version:


Languages which relate the subject of the intransitive verb with the object of a transitive verb in terms of a shared case form, for example, are called Ergative languages and while it is doubtful whether the phenomenon demonstrated in (44) has anything to do with the ergativity we find in languages like Basque or Eskimo languages such as Yupik, the term is a convenient one.

The transitive version of ergative verbs all have agentive subjects and theme objects. A first attempt at representing the structure of a VP headed by an ergative might be:


Unfortunately this is an entirely different set of Θ-role assignments to what we have previously found. We concluded above that the theme Θ-role is assigned to the specifier of a thematic verb, not its complement position. The agent, on the other hand, was assigned to the specifier of a light verb taking a VP complement. If we are to maintain the UTAH, either the structure in (45) is inaccurate, or our analyses of unaccusative and light verbs is.

Moreover, the structure of the VP in (45) is simple, in comparison to that of verbal complexes involving light verbs, as in (32), for example. Yet the event structure expressed here is not simple. In the butler opened the door, there is an event involving the butler doing something and an event involving the door being open and clearly the first event causes the second. Hence the event structure is:

(46)e = e1 → e2: e1 = ‘the butler did something’
  e2 = ‘the door opened’

If (45) is the correct analysis, then there is a mismatch here between event structure and syntactic structure whereas in other cases we have seen there has been an isomorphism between the two.



        Potential problems

        Light verbs and ergatives

        Unaccusatives and ergatives