The preterite of demostrar is used to express a specific instance of demonstrating or proving something in the past, for example El científico demostró su teoría en el laboratorio (The scientist demonstrated their theory in the laboratory). This tense emphasizes the completed action at a particular moment.

This is a regular -ar verb that follows the standard preterite conjugation pattern. Its straightforward conjugation makes it an excellent example for practicing regular preterite forms.

Conjugations

Conjugations of Demostrar (to demonstrate) in the Preterite (Past) Tense tense (Latin American Spanish):

The preterite of demostrar expresses a completed action of demonstrating or proving in the past.

To demonstrate/prove: Describes showing or proving something conclusively, for example Demostró su inocencia en el juicio (He/she proved their innocence at the trial) or El científico demostró su teoría (The scientist proved their theory).

To show/display: Used for showing feelings or qualities, for example Demostró gran valentía (He/she showed great courage).

Examples

Examples of Demostrar in the Preterite (Past) Tense

El científico demostró su teoría en el laboratorio. (The scientist demonstrated their theory in the laboratory.)

Demostré mis habilidades en la entrevista. (I demonstrated my skills in the interview.)

Demostraste gran valentía en ese momento. (You demonstrated great courage in that moment.)

Demostramos nuestro compromiso con el proyecto. (We demonstrated our commitment to the project.)

Los estudiantes demostraron su conocimiento en el examen. (The students demonstrated their knowledge in the exam.)

El equipo demostró su superioridad en el campo. (The team demonstrated their superiority on the field.)

Demostré mi inocencia ante el juez. (I demonstrated my innocence before the judge.)

Demostraste tu talento musical en el recital. (You demonstrated your musical talent at the recital.)

La empresa demostró su liderazgo en el mercado. (The company demonstrated its leadership in the market.)

Demostramos nuestra solidaridad con la causa. (We demonstrated our solidarity with the cause.)

Los artistas demostraron su creatividad en la exposición. (The artists demonstrated their creativity at the exhibition.)

Demostré mi lealtad al equipo. (I demonstrated my loyalty to the team.)

Demostraste ser un verdadero amigo. (You demonstrated being a true friend.)

El atleta demostró su resistencia en la maratón. (The athlete demonstrated their endurance in the marathon.)

Demostramos nuestro valor en la competencia. (We demonstrated our worth in the competition.)

Conjugations with English Translations

Conjugations of Demostrar (to demonstrate) in the Preterite (Past) Tense tense (Latin American Spanish) with English Translations:

This post covers Latin American Spanish. For Castilian Spanish, click here

Synonyms

The Preterite tense is also known as the Simple Past, Past Simple, Definite Past, Absolute Past, or Past Tense Indicative in English, and as Pretérito Perfecto Simple, Pretérito Indefinido, Pretérito Simple, Pasado Simple, or Pretérito de Indicativo in Spanish.