In order to determine whether a language uses symmetric or asymmetric negation, sentences that fulfill the following criteria must be considered:
- feature main clauses
- are declarative
- are affirmative
- contain a finite verb
The entire sentence (the verbal predicate) must be negated. This parameter examines whether verb forms in negative sentences differ from their affirmative counterparts. If the only difference between a negative and affirmative sentence is the appearance of a negative morpheme (word or affix), standard negation is considered symmetric. If the negative sentence also shows differences in its verb form, standard negation is considered asymmetric. Asymmetric negation displays further subtypes, which are not considered here. Languages may also display both symmetry and asymmetry in their negation. The use of one type over another may be freely chosen or grammatically restricted based on tense, aspect, or mood. Languages that display both types are considered mixed.
Sym: Standard negation is symmetric.
Asym: Standard negation is asymmetric.
When a language displays both types, multiple values can be listed. If one type is dominant, a slash (/) can separate the two values, with the dominant value appearing first; if neither is dominant, they are listed with an ampersand (&) separating the two. Dominance should be clearly defined in the commentary. In listing both types, care should be given to avoid overrepresentation of sporadic use of one type.
 Copular predicates are not considered for this parameter.
 These differences should be strictly syntactic in nature; morphophonological differences are not relevant for this parameter. Furthermore, variation in other parts of the sentence, such as case endings on the object of the verb, is not considered.
 Asymmetry is not paradigmatic if verb forms expressing verbal categories such as person, number, tense, aspect, and mood are the same across affirmative and negative sentences, with negation differentiated merely by the use of a special morpheme. In contrast, paradigmatic asymmetry does occur when certain verbal categories, particularly tense, aspect, and mood, are distinguished in affirmative sentences but not their negative counterparts. For discussion of the subtypes of asymmetric negation, see the parameter Subtypes of asymmetric standard negation.