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Spanish · Verb · #143 most common

demostrar

to demonstrate
to proveevidence

Irregular-ar ending

In the tables below, the stem is shown in black and the ending in purple.

1.

Presente

Habitual actions, general truths, and what's happening now.

yodemuestro
demuestras
él/ellademuestra
nosotrosdemostramos
vosotrosdemostráis
ellos/ellasdemuestran

Ella demuestra su talento en cada actuación.

She demonstrates her talent in every performance.

Los científicos demuestran sus teorías con experimentos.

Scientists demonstrate their theories with experiments.

2.

Pretérito Indefinido

Completed actions at a specific point in the past.

yodemostré
demostraste
él/ellademostró
nosotrosdemostramos
vosotrosdemostrasteis
ellos/ellasdemostraron

Ayer, él demostró que tenía razón.

Yesterday, he demonstrated that he was right.

El profesor demostró la fórmula en clase.

The teacher demonstrated the formula in class.

3.

Imperfecto

Ongoing or repeated actions in the past, descriptions, and background context.

yodemostraba
demostrabas
él/ellademostraba
nosotrosdemostrábamos
vosotrosdemostrabais
ellos/ellasdemostraban

Cuando era niño, siempre demostraba curiosidad por la ciencia.

When I was a child, I always demonstrated curiosity about science.

Ella demostraba su amor con pequeños gestos.

She demonstrated her love with small gestures.

4.

Futuro Simple

Future actions, predictions, and speculation about the present.

yodemostraré
demostrarás
él/ellademostrará
nosotrosdemostraremos
vosotrosdemostraréis
ellos/ellasdemostrarán

Mañana, ellos demostrarán sus habilidades en la competencia.

Tomorrow, they will demonstrate their skills in the competition.

Yo demostraré que puedo hacerlo.

I will demonstrate that I can do it.

5.

Condicional

Hypothetical situations, polite requests, and future-in-the-past.

yodemostraría
demostrarías
él/ellademostraría
nosotrosdemostraríamos
vosotrosdemostraríais
ellos/ellasdemostrarían

Si tuviera tiempo, demostraría cómo se hace.

If I had time, I would demonstrate how it's done.

Ella demostraría su punto si le dieran la oportunidad.

She would demonstrate her point if given the opportunity.

6.

Subjuntivo Presente

Wishes, doubts, emotions, and subordinate clauses expressing uncertainty.

yodemuestre
demuestres
él/ellademuestre
nosotrosdemostremos
vosotrosdemostréis
ellos/ellasdemuestren

Es importante que él demuestre su compromiso.

It is important that he demonstrates his commitment.

Espero que ellos demuestren su talento en el concurso.

I hope that they demonstrate their talent in the contest.

7.

Subjuntivo Imperfecto

Past subjunctive contexts, hypothetical si-clauses, and polite suggestions.

yodemostrara
demostraras
él/ellademostrara
nosotrosdemostráramos
vosotrosdemostrarais
ellos/ellasdemostraran

Si él demostrara más interés, podría aprender más.

If he demonstrated more interest, he could learn more.

Ojalá que ella demostrara su habilidad en el proyecto.

I wish she would demonstrate her skill in the project.

"demostrar" in other languages

Related verbs

Common questions
Is "demostrar" regular or irregular in Spanish?
"demostrar" is an irregular Spanish verb. It does not follow the standard -ar conjugation pattern and must be memorized.
How do you conjugate "demostrar" in the present tense?
In the Presente, "demostrar" conjugates as: demuestras, demuestro, demuestran, and more. See the full table above.
What is the past tense of "demostrar" in Spanish?
In the Pretérito Indefinido, "demostrar" conjugates as: demostraste, demostré, demostraron, and more. See the full table above.
How common is "demostrar" in Spanish?
"demostrar" (to demonstrate, to prove) is one of the most commonly used verbs in Spanish.