substituer

Substituer is a French verb meaning to replace someone or something with another person or thing. It is used across a range of contexts, including everyday language, sports, science, and philosophy, to indicate a temporary or permanent replacement or substitution.

Etymology and sense: substituer comes from Latin substituere, via Old French, and combines the prefix sub- with statuere “to set.” The sense evolved to cover replacing one element by another, whether in objects, people, roles, or concepts. In practice, it often implies an intentional choice to put something in the place of something else.

Usage and nuances: Substituer X à Y (to substitute X for Y) or substituer Y par X are common constructions. In sport, a coach may substitute a player during a match. In medicine or daily life, one might substitute sugar with honey, or substitute a drug with an alternative treatment. In science and logic, substitution denotes replacing a variable or component with another.

Conjugation: Substituer is a regular -er verb. Present tense forms are je substitue, tu substitues, il substitue, nous substituons, vous substituez, ils substituent. The verb also forms the passé composé (j’ai substitué), imperfect (je substituais), future (je substituerai), and subjunctive (que je substitue, que nous substituions).

Contexts and related terms: The noun substitutions (substitution, substitut) and related adjectives such as substitutif appear in discussions of chemistry (réaction de substitution), linguistics, and mathematics. In many contexts, substituer carries a formal or technical nuance compared with simpler verbs like remplacer.