Outside LFG, the term `subjectless' is found referring to a range of phenomena in which the expression of the predicate lacks an overt lexical item (a syntactic constituent) bearing the grammatical function of the subject. In some of these phenomena, for example in pro-drop, the architecture of LFG allows us to find the subject at the a-structure and f-structure levels despite there being no categorial element expressing the subject. There are, however, other subjectless constructions for which there are no readily available LFG accounts, and it is not always obvious how they could be analysed adequately. It is constructions of this type -- often called `impersonal' in traditional literature -- that are the focus of this paper, exemplified from Polish which is rich in impersonal forms.
I begin with an overview of all Polish constructions which appear to be subjectless and identify three types of construction which lack subjects at some level of analysis: pro-drop constructions (including the so-called `weather constructions' and `adversity impersonals'), morpholexically derived impersonal constructions (including the reflexive impersonal and the impersonal involving a form ending in -no/-to), and truly subjectless constructions (including inherently impersonal predicates and passives of intransitives). I demonstrate how they differ by highlighting their morphological and syntactic properties and suggest levels of representation at which the different types of `null/missing subjects' can be captured theoretically.