In many languages, there are "ambitransitive" verbs, which can occur either in a transitive or intransitive sense. For example, English
play is ambitransitive, since it is grammatical to say
His son plays, and it is also grammatical to say
His son plays guitar. English is rather flexible as regards verb valency, and so it has a high number of ambitransitive verbs; other languages are more rigid and require explicit valency changing operations (
voice,
causative morphology, etc.) to transform a verb from intransitive to transitive or vice versa. In some ambitransitive verbs are
ergative verbs for which the alignment of the syntactic arguments to the semantic roles is exchanged. An example of this is the verb
break in English. :(1)
broke . :(2)
broke. In (1), the verb is transitive, and the subject is the
agent of the action, i.e. the performer of the action of breaking the cup. In (2), the verb is intransitive and the subject is the
patient of the action, i.e. it is the thing affected by the action, not the one that performs it. In fact, the patient is the same in both sentences, and sentence (2) is an example of implicit
middle voice. This has also been termed an
anticausative or
inchoative, indicating a change of state without an external cause. Other alternating intransitive verbs in English are
change and
sink. In the
Romance languages, these verbs are often called
pseudo-reflexive, because they are signaled in the same way as
reflexive verbs, using the
clitic particle
se. Compare the following (in
Spanish): :(3a) ("The cup broke.") :(3b) ("The boat sank.") :(4a) ("She looked at herself in the mirror.") :(4b) ("The cat washes itself.") Sentences (3a) and (3b) show Romance pseudo-reflexive phrases, corresponding to English alternating intransitives. As in
The cup broke, they are inherently without an agent; their
deep structure does not and can not contain one. The action is not reflexive (as in (4a) and (4b)) because it is not performed by the subject; it just happens to it. Therefore, this is not the same as
passive voice, where an intransitive verb phrase appears, but there is an implicit agent (which can be made explicit using a complement phrase): :(5) ("The cup was broken (by the child).") :(6) ("The boat was sunk (by pirates).") Other ambitransitive verbs (like
eat) are not of the alternating type; the subject is always the agent of the action, and the object is simply optional. A few verbs are of both types at once, like
read: compare
I read,
I read a magazine, and
this magazine reads easily. Some languages like Japanese have different forms of certain verbs to show transitivity. For example, there are two forms of the verb "to start": : (7) : (8) In Japanese, the form of the verb indicates the number of arguments the sentence needs to have. ==Unaccusative and unergative verbs==