Impersonal (definition)
From Scottish Gaelic Grammar Wiki
Definition
An 'impersonal' is a type of verb that is singular, third person, and does not have a specified agent semantic/thematic role. This type of verb does not and cannot have a subject, although in languages that require a subject position to be filled, the subject must be non-referential, meaningless (e.g., "It rained.").
See Also
Thematic Relation (definition)
External Links
SIL entry on impersonal verb
Wikipedia entry on impersonal verb
References
SIL entry on impersonal verb
Wikipedia entry on impersonal verb