Prevenir in the Preterite Tense
Prevenir means “to prevent, to warn”, and this page covers exactly one thing: prevenir in the preterite tense. The preterite is the tense Spanish speakers reach for when they talk about what is finished and done. On this page you will find the full preterite table for prevenir, how the tense is formed for this verb, the situations where it is used, how it differs from the imperfect, worked examples, the mistakes learners make most often, an eight-question quiz with explained answers, and answers to the questions students ask about prevenir in the preterite. For example: “Ayer, yo previne accidentes en el trabajo.” — Yesterday, I prevented accidents at work. Everything on this page uses the forms of prevenir exactly as they are conjugated in the preterite, so you can trust every form you see here.
Prevenir in the Preterite Tense — full table
| Person | Form |
|---|---|
| yo | previne |
| tú | previniste |
| él/ella/Ud. | previno |
| nosotros/as | previnimos |
| vosotros/as | previnisteis |
| ellos/ellas/Uds. | previnieron |
Gerund: previniendo · Past participle: prevenido
The gerund is previniendo, which you use with estar to say what is happening right now: “Estoy previniendo” means the action of prevenir is in progress at this very moment. The past participle is prevenido, which you use with haber in the perfect tenses: “he prevenido” is the present perfect, used for a completed action. Keep both forms in mind as you read the examples below, because the preterite is only one part of how prevenir is used.
How the preterite of prevenir is formed
Prevenir does not use one regular stem in this tense, so the forms below do not follow the simple stem + endings pattern. This tense is irregular for this verb: it follows the pattern of venir, with changes in the present, the preterite (the -vin- stem), the future and conditional, and the subjunctive. Learn the forms in the table rather than applying the regular endings. Learn the six forms as a set: yo previne, tú previniste, él/ella/Ud. previno, nosotros/as previnimos, vosotros/as previnisteis, ellos/ellas/Uds. previnieron.
When to use the preterite of prevenir
The preterite is not a single-purpose tense. Below are the five situations where you will use prevenir in the preterite most often. Each one comes with a real example, so read the rule, then say the example out loud.
1. One finished action
The preterite reports a single action that started and finished in the past. The action is done, counted once, and the story moves on. Example: “Ayer, yo previne accidentes en el trabajo.” — Yesterday, I prevented accidents at work.
2. A sequence of events
In a story, each preterite form is one step forward in time. When several things happened one after another, the preterite lists them in order. Example: “Nosotros previnimos a los vecinos del corte de agua.” — We prevented the neighbours about the water cut.
3. A specific time marker
Time words such as ayer, anoche, el año pasado and la semana pasada point to the preterite. They name a finished moment, and the verb must match. Example: “Él previno enfermedades con la vacuna ayer.” — He prevented illnesses with the vaccine yesterday.
4. A sudden change or interruption
The preterite describes sudden changes and interruptions: something happened, and the situation was different afterwards. Example: “Ellos previnieron a su hijo del peligro de repente.” — They prevented his son about the danger suddenly.
5. A completed time frame
When an action took place inside a period of time that is now over, the preterite is the right tense, because the period itself is finished. Example: “Tú previniste accidentes en el trabajo la semana pasada.” — You prevented accidents at work last week.
Preterite Tense vs Imperfect: how to choose
The closest tense to the preterite is the imperfect, and choosing between them is one of the hardest decisions in Spanish. The rule is simple: the preterite reports one finished action, while the imperfect describes background, habits in the past, or an action that was in progress when something else happened. The three pairs below use the same verb, so the only thing that changes is whether the action is finished and counted, or ongoing and descriptive. Time words help: ayer and de repente point to the preterite, while mientras and todos los días in the past point to the imperfect.
Preterite Tense: “Ayer, yo previne accidentes en el trabajo.” — Yesterday, I prevented accidents at work.
Imperfect: “Yo prevenía accidentes en el trabajo cada día.” — I used to prevent accidents at work every day.
The preterite sentence reports one finished action; the imperfect sentence describes a habit in the past. Ayer points to the preterite, cada día in the past points to the imperfect.
Preterite Tense: “Anoche, él previno a los vecinos del corte de agua.” — Last night, he prevented the neighbours about the water cut.
Imperfect: “Él prevenía a los vecinos del corte de agua todos los días.” — He used to prevent the neighbours about the water cut every day.
Anoche names one finished night, so the preterite is right; todos los días in the past describes a routine, so the imperfect is right.
Preterite Tense: “Nosotros previnimos enfermedades con la vacuna ayer.” — We prevented illnesses with the vaccine yesterday.
Imperfect: “Nosotros preveníamos enfermedades con la vacuna cuando éramos jóvenes.” — We used to prevent illnesses with the vaccine when we were young.
The preterite sentence counts one finished action; the imperfect sentence describes how things used to be. That difference — finished event versus background — is the whole decision.
Example sentences: prevenir in the preterite
Read these eight sentences out loud. They cover all six persons, so by the end you will have seen every form in the table used in a real sentence. Pay attention to the words around the verb — the time expressions, the objects, the other verbs — because those are what make each sentence sound natural.
“Previne accidentes en el trabajo.” — I prevented accidents at work.
“Previniste a los vecinos del corte de agua.” — You prevented the neighbours about the water cut.
“Previno enfermedades con la vacuna.” — He/she prevented illnesses with the vaccine.
“Previnimos a su hijo del peligro.” — We prevented his son about the danger.
“Previnisteis accidentes en el trabajo.” — You prevented accidents at work.
“Previnieron a los vecinos del corte de agua.” — They prevented the neighbours about the water cut.
“Previne enfermedades con la vacuna.” — I prevented illnesses with the vaccine.
“Previno a su hijo del peligro.” — He/she prevented his son about the danger.
Common mistakes with prevenir in the preterite
These are the errors learners actually make with this verb in this tense. Each one shows the wrong version, the right version, and why the correction matters.
Wrong: “Ellos previno accidentes en el trabajo.” Right: “Ellos previnieron accidentes en el trabajo.” Why: Ellos needs the ellos form previnieron. The singular previno belongs with él, ella or a singular noun.
Wrong: “Ayer yo prevení a los vecinos del corte de agua.” Right: “Ayer yo previne a los vecinos del corte de agua.” Why: Prevenir has an irregular preterite: the correct first-person form is previne, not the regular prevení.
Wrong: “Nosotros previniste enfermedades con la vacuna.” Right: “Nosotros previnimos enfermedades con la vacuna.” Why: Nosotros needs previnimos. The tú form previniste belongs with tú.
Wrong: “Ellos previne a su hijo del peligro.” Right: “Ellos previnieron a su hijo del peligro.” Why: The verb must agree with its subject. Ellos needs the ellos form previnieron, not the yo form previne.
Quiz: prevenir in the preterite
Choose the correct answer for each question, then check the answer key. Every answer is explained, so a wrong answer still teaches you something.
1. Complete the sentence: “Yo ______ accidentes en el trabajo.” (Accidents at work.)
- (a) previne
- (b) previniste
- (c) previno
Answer: previne — The yo form of prevenir in the preterite is previne. The other options are the forms for different persons, so they do not agree with the subject.
2. Complete the sentence: “¿Tú ______ a los vecinos del corte de agua?” (The neighbours about the water cut.)
- (a) previne
- (b) previno
- (c) previniste
Answer: previniste — The tú form of prevenir in the preterite is previniste. The other options are the forms for different persons, so they do not agree with the subject.
3. Complete the sentence: “Él ______ enfermedades con la vacuna.” (Illnesses with the vaccine.)
- (a) previniste
- (b) previno
- (c) previne
Answer: previno — The él/ella/Ud. form of prevenir in the preterite is previno. The other options are the forms for different persons, so they do not agree with the subject.
4. Complete the sentence: “Nosotros ______ a su hijo del peligro.” (His son about the danger.)
- (a) previnimos
- (b) previne
- (c) previniste
Answer: previnimos — The nosotros/as form of prevenir in the preterite is previnimos. The other options are the forms for different persons, so they do not agree with the subject.
5. What is the vosotros/as form of prevenir in the preterite?
- (a) previne
- (b) previniste
- (c) previnisteis
Answer: previnisteis — From the table above: vosotros/as takes previnisteis. Say it with the example sentence “Vosotros previnisteis accidentes en el trabajo.” to fix it in your memory.
6. Complete the sentence: “Ellos ______ a los vecinos del corte de agua.” (The neighbours about the water cut.)
- (a) previniste
- (b) previnieron
- (c) previne
Answer: previnieron — The ellos/ellas/Uds. form of prevenir in the preterite is previnieron. The other options are the forms for different persons, so they do not agree with the subject.
7. Which is the correct yo form of prevenir in the preterite?
- (a) previne
- (b) previniste
- (c) previno
Answer: previne — The yo form is previne. The other two options are the forms for other persons.
8. Which sentence describes one finished action in the past?
- (a) Yo prevenía accidentes en el trabajo cada día.
- (b) Mañana, yo prevendré accidentes en el trabajo.
- (c) Ayer, yo previne accidentes en el trabajo.
Answer: Ayer, yo previne accidentes en el trabajo. — “Ayer, yo previne accidentes en el trabajo.” reports a single completed event, so it takes the preterite. The second option describes background or a past habit, and the third looks to the future.
Frequently asked questions
Is prevenir regular in the preterite?
No. Prevenir has an irregular preterite: previne, previniste, previno, previnimos, previnisteis, previnieron. Learn these forms as a set rather than deriving them from the infinitive.
What is the past participle of prevenir?
The past participle is prevenido: 'He prevenido' means 'I have prevented'. It is used with haber in every perfect tense. The gerund is previniendo.
When do I use the preterite instead of the imperfect for prevenir?
Use the preterite for one finished action, as in Ayer, yo previne accidentes en el trabajo. Use the imperfect for a repeated habit or background, as in Yo prevenía accidentes en el trabajo cada día. The time words around the verb usually tell you which one fits.
How do I remember the preterite forms of prevenir?
Say the six forms out loud in order, three times, with a real sentence for each one: yo previne, tú previniste, él/ella/Ud. previno, nosotros/as previnimos, vosotros/as previnisteis, ellos/ellas/Uds. previnieron. Then write three of your own sentences with prevenir in the preterite, using the examples on this page as models.
Related pages
- Full conjugation of prevenir — every tense of prevenir in one place.
- Prevenir examples and quiz — more sentences with prevenir and a ten-question quiz.
- Spanish preterite guide — how the preterite works for all Spanish verbs.
- Spanish verbs — the hub for every Spanish verb on VerbFlow.
- Preterite conjugator — conjugate any verb in the preterite instantly.
- Verb quiz — test yourself on prevenir and other verbs.