Unaccusative verb

In modern linguistics, an unaccusative verb is an intransitive verb whose grammatical subject is not a semantic agent. In other words, it does not actively initiate or is not actively responsible for the action of the verb. In modern linguistics, an unaccusative verb is an intransitive verb whose grammatical subject is not a semantic agent. In other words, it does not actively initiate or is not actively responsible for the action of the verb. An unaccusative verb's subject is semantically similar to the direct object of a transitive verb or to the subject of a verb in the passive voice. Examples in English are 'the tree fell'; 'the man died'; 'the window broke'. In those sentences, the action (falling, dying, breaking) can be considered as something that happened to the subject, rather than being initiated by it. Semantically, the word 'tree' in the sentence 'the tree fell' plays a similar role as it does in a transitive sentence, such as 'they cut down the tree', or its passive transformation 'the tree was cut down'. Unaccusative verbs thus contrast with unergative verbs, such as run or resign, which describe actions voluntarily initiated by the subject. They are called unaccusative because although the subject has the semantic role of a patient, it is not assigned accusative case. In nominative–accusative languages, the accusative case, which marks the direct object of transitive verbs, usually represents the non-volitional argument (often the patient). However, for unaccusative verbs, although the subject is non-volitional, it is not marked by the accusative. As Perlmutter points out, the same verb such as 'slide' can be either unaccusative or unergative, depending on whether the action was involuntary or voluntary. The term 'unaccusative verb' was first used in a 1978 paper by David M. Perlmutter of the University of California, San Diego. According to Perlmutter himself, the terms 'unaccusative' and 'unergative' were both invented by the linguist Geoffrey K. Pullum. As mentioned above, the unaccusative/unergative split in intransitive verbs can be characterized semantically. Unaccusative verbs tend to express a telic and dynamic change of state or location, while unergative verbs tend to express an agentive activity (not involving directed movement). While these properties define the 'core' classes of unaccusatives and unergatives, there are intermediate classes of verbs whose status is less clear (for example, verbs of existence, appearance, or continuation, verbs denoting uncontrolled processes, or motion verbs). A number of syntactic criteria for unaccusativity have also been identified. The most well-known test is auxiliary selection in languages that use two different temporal auxiliaries (have and be) for analytic past/perfect verb forms (e.g. German, Dutch, French, Italian; even Early Modern English). In these languages, unaccusative verbs combine with be, while unergative verbs combine with have.