The forms share one criterion—additional wording that produces a benefit—but they achieve it in different ways.
FormParticular contribution
Clarification after ambiguityIdentification after expectation
TawshīʿNaming the two members of a dual
Specific after generalSpecial prominence for one member
RepetitionGreater emphasis, warning or urgency
ĪghālEnhancement at the end of a poetic line
Apparent union of incompatibles brings a further effect through the resolution of apparent conflict. The subsequent section, tadhyīl, introduces another mode of explanatory or emphatic supplementation.