Literal usage follows the sense assigned by the relevant convention. Figurative usage requires a different intended sense, a valid relation, and a contextual indicator excluding the literal one. Non-similarity grounds majāz mursal; resemblance grounds metaphor.
Metaphor requires identification of source and target. The resemblance may be sensory or conceptual, the borrowed form underived or derivative, and further accompanying wording may make it unqualified, target-oriented, or source-reinforced.
These criteria distinguish literal usage, metonymy, primary and derivative metaphor, and the devices of abstraction and reinforcement. More intricate constructions and consequences of metaphor continue in the next section.