A grammatical figure (figura constructionis) is one that depends upon some manipulation of specific grammatical elements, or which purposefully alters normal grammatical conventions for effect. Grammatically based figures are often simply the purposeful or artistic use of grammatical vices.
This classification of figures has by no means been universal over time. The following list is a synthesis.
Many grammatical figures are syntactical, relying upon some arrangement, manipulation, or emphasis of syntax. These are in fact grammatical schemes.
anacolouthon (A grammatical interruption or lack of implied sequence within a sentence.)
anapodoton (A figure in which a main clause is suggested by the introduction of a subordinate clause, but that main clause never occurs.)
asyndeton (The omission of conjunctions between clauses, often resulting in a hurried rhythm or vehement effect.)
polysyndeton (Employing many conjunctions between clauses, often slowing the tempo or rhythm.)
zeugma (A general term describing when one part of speech (most often the main verb, but sometimes a noun) governs two or more other parts of a sentence (often in a series))
syllepsis (When a single word that governs or modifies two or more others must be understood differently with respect to each of those words.)
appositio (Addition of an adjacent, coordinate, explanatory or descriptive element.)
Some grammatical figures depend upon some sort of grammatical substitution:
enallage (The substitution of grammatically different but semantically equivalent constructions.)
antiptosis (A type of enallage in which one grammatical case is substituted for another.)
Some grammatical figures may in fact be errors or vices (or the purposeful use of these):
solecismus (An element of speech or writing that is incorrect grammatically.)
synchysis (The confused arrangement of words in a sentence; hyperbaton or anastrophe taken to an obscuring extreme, either accidentally or purposefully.)