Passive constructions (PassCstr) generally appear in nominative–accusative languages. A construction is considered passive if it fulfills the following three criteria:
- It has an equivalent active construction featuring a transitive verb.
- If present, the agent (the subject of the active construction) appears in an adjunct, marked by an oblique case.
- The subject of the sentence is the patient of the verb, or the object of the active construction.
The agent of a passive construction (the subject of the equivalent active construction) is grammatically “demoted” or “deranked”: it is either entirely eliminated from the sentence or relegated to an adjunct, generally functioning as an adverbial with oblique case marking. Demotion of the agent alone does not, however, qualify a construction as passive, if it fails to meet the two other criteria listed above.
This parameter considers the verbal morphology of passive constructions. There are two possible strategies for expressing the passive on the verb: synthetic (also known as morphological) and analytic (also known as periphrastic). The synthetic approach marks the passive within the morphology of the verb itself, while the analytic approach relies on a periphrastic construction featuring the main verb alongside an auxiliary verb.
NoPass: The language does not use passive constructions.
PassNoV: In passive constructions, the passive is not marked on the verb.
PassSynt: Passive constructions are synthetic.
PassAn: Passive constructions are analytic.
When a language displays both PassSynt and PassAn, both values can be listed. If one type is dominant (appearing in more tenses, aspects, and moods), a slash (/) can separate the two, with the dominant value appearing first; if neither is dominant, they are listed with an ampersand (&) separating them.
 Constructions with a generic subject (such as the German man or English one) are therefore not passive. Other structures that do not constitute passives include active constructions with a null subject, medial verbs (also known as anti-causatives, which express events or states), and the use of a reflexive or reciprocal affix when the subject of the sentence cannot serve as the object of an equivalent active construction (such as the Russian собака кусается ‘the dog bites,’ literally ‘bites itself’), and constructions in which an adverbial modifying the agent’s action (such as on purpose) cannot appear alongside the verb. Similarly, neither the topic-oriented sentences of the Philippine languages (also known as “focus-system constructions”) nor the inverse constructions of the Algonquin languages can be considered passive constructions.
 This value applies to all non-nominative (including ergative) languages, as well as nominative languages that do not use passive structures. If the NoPass value applies to a language for this parameter, it will automatically apply for the Parapassive parameter as well.