This parameter considers the existence of specific forms of the second-person singular in the prohibitive, with reference to its counterparts in the affirmative imperative and negative (indicative) declarative.

The prohibitive may display distinct forms in two ways: (1) the verb form used for the prohibitive differs from that of the affirmative imperative, and (2) the strategy used to express prohibition differs from that of negative declarative[1]. Across languages, the prohibitive may differ in one, both, or neither of each two ways, resulting in four possible types. If multiple strategies are possible within a language, the distinct types should be considered, unless these are not characteristic of actual use.[2]

Types:

Proh=ImpNegNonspec: Prohibitive and affirmative imperative verb forms are the same, with negation expressed using the same strategy as in negative declarative sentences.

Proh=ImpNegSpec : Prohibitive and affirmative imperative verb forms are the same, with negation expressed using a different strategy than in negative declarative sentences.

ProhNonImpNegNonspec: Prohibitive verb forms differ from affirmative imperative verb forms, while the strategy used for negative is the same as that in declarative sentences.

ProhNonImpNegSpec: Prohibitive verb forms differ from affirmative imperative verb forms, with negation expressed using a different strategy than in negative declarative sentences.

[1] Strategies may include a negative word or verb.

[2] In either case, the types should be detailed in the commentary.