demostrar
verbCEFR B2
What does “demostrar” mean in English?
to demonstrate, to prove
to demonstrate, to prove (to show evidence for; demostrar que + indicative — evidence-based argument)
Example sentences
El estudio demuestra que las intervenciones tempranas reducen significativamente el riesgo de recaída.
The study demonstrates that early interventions significantly reduce the risk of relapse.
Los hechos demuestran que la política adoptada no ha dado los resultados esperados.
The facts demonstrate that the adopted policy has not delivered the expected results.
La investigación no ha podido demostrar una relación causal entre los dos fenómenos.
The research has not been able to demonstrate a causal relationship between the two phenomena.
How to use it
Demostrar means 'to demonstrate' or 'to prove' — providing evidence that establishes a fact. Key frame: demostrar que + indicative (the speaker asserts the truth of what follows). Stem-changing: demuestra, demuestran. Distinct from mostrar (show/display, without proof implications) and probar (prove, also common but often in legal contexts).
Common mistake
Demostrar que always takes indicative — the speaker treats the demonstrated fact as established. Don't use subjunctive in positive demostrar que clauses. Demostrar vs. mostrar: demostrar implies evidence and proof; mostrar just means to show or display. Stem-changing: demuestra (not *demonstra).