The syntheticism of verbal inflection in a given language is numerically represented by its category-per-word value. Abbreviated as cpw value, this number refers to the maximum inflectional categories that a single verb form can express simultaneously.[1] Inflectional categories are grammatical features whose expression requires a distinct form of the verb.[2]

Grammatical features can be expressed through the use of independent words, which is known as an analytic strategy, or affixes, which is known as a synthetic strategy. Synthetic strategies rely on morphological, rather than syntactic, relations between their components.[3]

Types:

CpW=0: The language does not have verbal inflection.

CpW=x: The category-per-word value is x.

[1] In most languages, the cpw value is a lower number than the total number of verbal inflectional categories. (See parameter Number of verbal inflectional categories.) This often occurs because certain features cannot be marked across the full paradigm, thus limiting their co-occurrence with other features.

[2] The most common verbal inflectional categories are person and number; time, aspect, and mood (TAM); agreement, evidentiality (evidentiality vs. reportativity and/or mirative), status (realis–irrealis), polarity (affirmative–negative), illocution (declarative, interrogative, imperative), and voice. Less frequently occurring inflectional categories include nominalization, collective marking, inversion, honorifics, target quantification, focus, transitivity, reciprocity (as a feature of agreement), argument markers, object classifiers, non-specific referent marking, scope, deixis, movement, causatives (if relevant to the context). TAM should only be counted as a single unit if these features are not grammatically distinct in the given language.

[3] It is possible for a verbal inflectional morpheme to be classified as synthetic despite consisting of phonologically distinct “words,” provided that the unit expressing the grammatical categories does not display syntactic independence. Syntactic relations are characterized by (1) the ability of their components to appear independently, (2) belonging to syntactically distinct nodes, (3) the lack of a fixed order among the given components, (4) the ability of these components to appear independently in order to mark focus, and (4) the presence of agreement among these components. If these criteria fail to be met, the presence of either independent stress or prosodic independence (consisting of more than one mora) may also indicate that a word is syntactically independent.