prevenir Imperfect Conjugation
prevenir — to prevent
Prevenir is completely regular in the imperfect: prevenía, prevenías, prevenía...
prevenir Imperfect Forms
When to Use the Imperfect
Use the imperfect to describe ongoing preventative measures in the past or background habits that used to prevent issues.
Notes on prevenir in the Imperfect
Prevenir is regular in the imperfect. All forms use the standard -ía endings for -ir verbs.
Example Sentences
Antes, la empresa prevenía las pérdidas con este sistema.
Before, the company used to prevent losses with this system.
él/ella/usted
Nosotros preveníamos los resfriados con vitaminas.
We used to prevent colds with vitamins.
nosotros
Las leyes prevenían el abuso de poder.
The laws were preventing the abuse of power.
ellos/ellas/ustedes
Common Mistakes
Mistake: previnía
Correct: prevenía
Why: The 'i' stem change from the preterite does not carry over to the imperfect.
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Related Tenses
Present
yo: prevengo
Prevenir is a stem-changing verb (e > ie) with a special 'yo' form: prevengo.
Preterite
yo: previne
Prevenir uses an irregular stem 'previn-' in the preterite: previne, previste, previno...
Future
yo: prevendré
Prevenir uses the irregular stem 'prevendr-': prevendré, prevendrás, prevendrá.
Conditional
yo: prevendría
Prevenir uses the irregular stem 'prevendr-' plus -ía endings.
Present Subjunctive
yo: prevenga
The present subjunctive uses the 'preveng-' stem: prevenga, prevengas, prevenga.
Imperfect Subjunctive
yo: previniera
Based on the preterite stem: previniera, previnieras, previniera.
Affirmative Imperative
yo: prevén
The affirmative commands are: prevén (tú), prevenga (usted), prevengamos (nosotros).
Negative Imperative
yo: no prevengas
Negative commands use 'no' + present subjunctive: no prevengas, no prevenga.