This parameter considers the strategies and word order used to express necessity (also known as deontic modality, abbreviated as Deon), including the use of affixes and independent words. Basic intransitive[1] sentences should be considered.

Types:

NoDeon: Necessity is expressed through clause-level strategies, rather than verbal modality.

NoMorfDeon: Necessity is expressed by a strategy that does not rely on separate, identifiable morphemes.[2]

PrefDeon: Necessity is expressed through the use of prefixes attaching to the verb stem.

InfDeon: Necessity is expressed through the use of infixes inserted into the verb stem.

SuffDeon: Necessity is expressed through the use of suffixes attaching to the verb stem.

CrcfDeon: Necessity is expressed through the use of circumfixes attaching to the verb stem.

VDeon:  Necessity is expressed through the use of an independent word that appears (indirectly or directly) after the verb.

DeonV:  Necessity is expressed through the use of an independent word that appears (indirectly or directly) before the verb.

When a language displays more than one strategy, multiple values can be listed, with the exception of NoDeon. If one type of strategy is dominant, a slash (/) can separate the values, with the dominant value appearing first; if there is no dominant strategies, the values should be listed with an ampersand (&) separating the two.

[1] For example, consider verbs such as come, go, etc.

[2] This value includes the use of internal flexion and tone.