demostráis

Demostráis is the present indicative form of the Spanish verb demostrar for the second person plural in the vosotros form, used mainly in Spain to mean you demonstrate or you prove. It expresses actions occurring in the present and can refer to proving a point, showing how something works, or presenting evidence.

Demostrar is a stem-changing -ar verb. In the present tense the forms are demuestro, demuestras, demuestra, demostramos, demostráis, demuestran. The o→ue change appears in all forms except the nosotros and vosotros forms, which are demostramos and demostráis, respectively, with the stress marked on the a in demostráis.

Usage note: Outside Spain, speakers typically use the vosotros form less often and replace it with ustedes demuestran. Examples: "Vosotros demostráis que la hipótesis es correcta." In Latin American dialects, one would say "ustedes demuestran." The term can be used in everyday language as well as in mathematical or scientific contexts to denote a demonstration or proof of a result.

Etymology: demostrar comes from Latin demonstrare, itself from de- "out" + monstrare "to show," related to the English word demonstrate.