A comparison is a proposition comprising a primum comparationis N₁ (Linda in the examples below), a secundum comparationis N₂ (sometimes called ‘standard of comparison’) (Sandra in the examples) and a tertium comparationis, a predicate P applying to both N₁ and N₂ which provides the parameter of comparison (intelligence in - ). In the simplest case, N₁ and N₂ are represented by nominal expressions. P is typically represented by a verb modified by an adjective or adverb. The proposition says that N₁ and N₂ are characterized by P in a way or to a degree D₁ and D₂, resp., and assesses D₁ with reference to D₂. Specification of D₁ and D₂ is no constitutive component of the comparative proposition; only their relation is coded.

If D₂ is equal to or like D₁, it is an equiparation (). If D₂ differs from D₁, it is a comparison of inequality. If D₁ represents a higher position on the parameter, it is a comparison of superiority (); in the opposite case, it is one of inferiority (). This relation may be specified by an operator of comparison. There are comparative propositions which lack N₂, saying that N₁ is comparatively P (); and there are others which lack P, saying just that N₁ is like or unlike N₂ (). On the other hand, P may be elaborated to different extents ().