sustituyo

Sustituyo is the first-person singular present indicative form of the Spanish verb sustituir. It translates roughly as “I substitute” or “I stand in for someone or something,” and is used to describe temporarily taking the place or function of another person, role, or element.

The verb sustituir is irregular in the present tense. The forms are: yo sustituyo, tú sustituyes, él/ella/usted sustituye, nosotros sustituimos, vosotros sustituís, ellos/ellas/ustedes sustituyen. The word comes from Latin substituere, meaning to place in place of or to substitute, and entered Spanish with a sense of temporary replacement or stand-in.

In usage, sustituir often conveys a temporary substitution rather than a permanent replacement. It is common in work, school, and daily life contexts where one person acts in another’s stead due to absence or unavailability. It is distinct from reemplazar, which generally implies a more permanent or complete replacement, or from suplantar, which carries nuances of substitution in a broader or more figurative sense.

Examples include: “Hoy sustituyo a mi colega en la clase” and “Yo sustituyo al profesor que está enfermo.” The corresponding participle is sustituyendo, and other tenses such as sustituyó (él) or sustituyera (imperfect subjunctive) exist to express different times and moods.