enallage

English

Examples (grammatically correct transformation)
He came, didn't he? for Didn't he come? There were mistakes made. for Mistakes were made. They may do what they want. for He or she may do what he or she wants.

Examples (grammatically incorrect substitution)
We was robbed for we were robbed.

From Ancient Greek ἐναλλαγή (enallagḗ, “interchange, variation”).

enallage (countable and uncountable, plural enallages)

(rhetoric) Transformation from one grammatically correct form to another.
(rhetoric) The substitution of one grammatical form for another that violates a grammatical rule.
- 1851, Goold Brown, The Grammar of English Grammars‎^[1]:
  And when all men shall have adopted this enallage, the fault indeed will be banished, or metamorphosed, but with it will go an other sixth part of every English conjugation.