Alertar Present Tense Conjugation in Spanish
The present tense of alertar — “to alert” in English — is the form you need for what happens now, for habits and for general truths. This page gives you the full present conjugation table for alertar with all six persons, explains exactly how the tense is formed for this verb, shows when to use it with real examples, and finishes with a quiz so you can test yourself. Alertar means to alert, to warn someone about a danger so they can act in time. It is used for weather, health, security and emergencies, and it is fully regular. To see it in a real sentence: Alerto a la población del peligro. — “I alert the population of the danger.” Learn the six forms in the table below, and the present tense of alertar will be ready for everyday conversation.
Present tense conjugation table: alertar
Every person of alertar in the present tense. The gerund is alertando and the past participle is alertado.
Present indicative
| Person | Form |
|---|---|
| yo | alerto |
| tú | alertas |
| él/ella/Ud. | alerta |
| nosotros/as | alertamos |
| vosotros/as | alertáis |
| ellos/ellas/Uds. | alertan |
How the present indicative of alertar is formed
The present indicative of alertar is built from the stem plus the present indicative endings for -ar verbs. Take the infinitive, drop the -ar ending, and add the ending that matches the person. The table below shows the endings, and the full table above shows them attached to the stem.
| Person | Ending | Form |
|---|---|---|
| yo | -o | alerto |
| tú | -as | alertas |
| él/ella/Ud. | -a | alerta |
| nosotros/as | -amos | alertamos |
| vosotros/as | -áis | alertáis |
| ellos/ellas/Uds. | -an | alertan |
Alertar is a regular -ar verb in the present tense, so the table above is completely regular. The stem is alert- and the endings are the normal -ar endings, so once you know the pattern you can produce every form on this page.
The gerund of alertar is alertando and the past participle is alertado. Both are regular for this verb, and the participle is the form you need for all the perfect tenses with haber.
When to use the present tense of alertar
The present tense is not one single use — it covers several situations, and alertar appears in all of them. The five uses below are the ones you will meet most often, each with an example that shows the verb in a natural sentence.
Routines and habits
Use the present for things you do regularly, every day or every week. The present is the tense of routine, and alertar fits naturally into daily life.
“Yo alerto a la población del peligro todos los días.” — “I alert the population of the danger every day.”
General facts
Use the present for facts that are true in general, not just today. When you state how something is, the present is the tense to use.
“Él alerta a los vecinos del incendio.” — “He/she alerts the neighbours about the fire.”
What is happening right now
Use the present for what is happening at this moment. Spanish often uses the simple present where English uses the progressive, so alerto can mean both “I alert” and “I am alerting”.
“Ahora mismo, yo alerto a la policía del robo.” — “Right now, I alert the police about the robbery.”
Fixed plans in the near future
Use the present for a plan that is already fixed, such as something arranged for tomorrow. Spanish uses the present for near-future plans much more freely than English does.
“Mañana, yo alerto sobre la tormenta que viene.” — “Tomorrow, I will alert about the coming storm.”
Questions and negatives
Use the present to ask about habits and to say what does not happen. The question and the negative use exactly the same forms as the statement.
“¿Tú alertas a la población del peligro?” — “Do you alert the population of the danger?”
The present tense vs the closest tenses
Present — habit or general fact vs Preterite — one finished occasion
The present describes a habit, a routine or a general fact — something that happens again and again or that is true in general. The preterite reports one finished occasion in the past. Use the present when the action repeats or is still true, and the preterite when you are telling what happened once, on a specific day.
- Present — habit or general fact: Alerta a los vecinos del incendio. — “He/she alerts the neighbours about the fire.”
- Preterite — one finished occasion: Alertó a los vecinos del incendio. — the same idea, placed in the preterite.
Present — now vs Imperfect — a past habit or background
The present talks about now. The imperfect talks about the past as a background — a repeated habit, an ongoing situation, something that used to happen. If you can add “used to” in English, the imperfect is usually the right choice; if it is happening now or always, use the present.
- Present — now: Alertan a la policía del robo. — “They alert the police about the robbery.”
- Imperfect — a past habit or background: Alertaban a la policía del robo. — the same idea, placed in the imperfect.
Present — now or a fixed plan vs Future — what will happen
The present describes what happens now, what you do regularly, or a plan that is already fixed. The future describes what will happen later — a promise, a prediction, a plan that is not yet under way. Spanish often uses the present for near-future plans, but the future is the form for a clear statement about tomorrow.
- Present — now or a fixed plan: Alertas sobre la tormenta que viene. — “You alert about the coming storm.”
- Future — what will happen: Alertarás sobre la tormenta que viene. — the same idea, placed in the future.
Examples: alertar in the present tense
Seven sentences that show alertar in the present tense only, across all six persons. Read each one aloud, notice the ending, and check the translation.
- Yo alerto a la población del peligro. — “I alert the population of the danger.”
- Tú alertas a los vecinos del incendio. — “You alert the neighbours about the fire.”
- Él alerta a la policía del robo. — “He alerts the police about the robbery.”
- Nosotros alertamos sobre la tormenta que viene. — “We alert about the coming storm.”
- Vosotros alertáis a la población del peligro. — “You (plural) alert the population of the danger.”
- Ellos alertan a los vecinos del incendio. — “They alert the neighbours about the fire.”
- ¿Tú alertas a la policía del robo? — “Do you alert the police about the robbery?”
Common mistakes with alertar in the present tense
These are the errors learners actually make with alertar in the present tense. Each one shows the wrong form, the right form, and why the right form is right.
✗ Yo alertar a la población del peligro. (using the infinitive instead of a conjugated form).
✓ Correct: Yo alerto a la población del peligro.
The infinitive is not a conjugated form. With yo, the present tense of alertar is alerto, not the infinitive alertar.
✗ Vosotros alertais a la población del peligro. (forgetting the accent on the vosotros form).
✓ Correct: Vosotros alertáis a la población del peligro.
The vosotros present form carries a written accent: alertáis, not alertais. The accent marks the stressed vowel, and leaving it out is a spelling mistake.
✗ Ayer, yo alerto a los vecinos del incendio. (using the present for a finished past action).
✓ Correct: Ayer, yo alerté a los vecinos del incendio.
The present and the preterite are different tenses: alerto is happening now, while alerté is a finished action in the past. Use the preterite with ayer.
✗ Treating alertar and avisar as identical in every context. (confusing alertar with avisar).
✓ Correct: Alertar means to alert, while avisar means to warn or notify.
They overlap, but each has uses the other does not: alertar fits sentences such as Alerto a la población del peligro, while avisar belongs in a different sentence. Check the meaning you want before choosing.
Quiz: alertar in the present tense
Eight questions on the present tense of alertar. Choose the best answer for each one, then check the answer key below — every answer is explained.
1. Which is the correct present tense form of alertar for tú?
- a) alertas
- b) alerto
- c) alerta
- d) alertan
2. Complete the sentence: Yo ______ a la población del peligro. — “I alert the population of the danger.”
- a) alerta
- b) alertamos
- c) alertas
- d) alerto
3. Complete the sentence: Él ______ a los vecinos del incendio. — “He/she alerts the neighbours about the fire.” (present tense)
- a) alertaba
- b) alertará
- c) alerta
- d) alertó
4. Which is the correct present tense form of alertar for nosotros?
- a) alertan
- b) alertamos
- c) alerto
- d) alerta
5. Which sentence uses alertar correctly in the present tense?
- a) Él alertó a los vecinos del incendio.
- b) Él alerta a los vecinos del incendio.
- c) Él alertará a los vecinos del incendio.
- d) Ellos alerta a los vecinos del incendio.
6. Complete the sentence: Ellos ______ a la policía del robo. — “They alert the police about the robbery.”
- a) alerto
- b) alerta
- c) alertamos
- d) alertan
7. Complete the question: ¿Tú ______ sobre la tormenta que viene? — “Do you alert about the coming storm?”
- a) alerta
- b) alertarás
- c) alertas
- d) alerto
8. What is the gerund of alertar?
- a) alerté
- b) alertando
- c) alertado
- d) alerto
Answer key
a) alertas — The tú form is alertas. The -s ending belongs to tú in the present; alerto is yo, alerta is él/ella and alertan is ellos/ellas.
d) alerto — The sentence needs the yo form in the present: alerto. The other options are the wrong person.
c) alerta — The sentence needs the él/ella/Ud. form in the present: alerta. The other options are the preterite, the imperfect and the future.
b) alertamos — Nosotros takes alertamos. In the present the nosotros ending for -ar verbs is -amos, attached to the stem.
b) Él alerta a los vecinos del incendio. — Él alerta a los vecinos del incendio. is correct: the verb agrees with its subject. The other sentences use the wrong person or the wrong tense.
d) alertan — The subject is ellos/ellas/Uds., so the present form is alertan.
c) alertas — The question needs the tú form in the present: alertas.
b) alertando — The gerund is alertando. It is the form you use with estar for the progressive (estar + gerund), and it is not the past participle alertado.
Frequently asked questions
Is alertar regular in the present tense?
Yes. Alertar is a regular -ar verb in the present tense, so the forms follow the standard endings: alerto, alertas, alerta, alertamos, alertáis and alertan.
What is the gerund and the past participle of alertar?
The gerund is alertando and the past participle is alertado. Use the gerund with estar for the progressive, and the participle with haber for the perfect tenses.
How do you say “I alert” in Spanish?
Say alerto. For example: Alerto a la población del peligro. — “I alert the population of the danger.”
What is the difference between alertar and avisar?
Alertar means “to alert”, while avisar means “to warn or notify”. They are related words that learners often meet together, but they are not interchangeable — use alertar when you mean “to alert” and avisar when you mean “to warn or notify”. The full conjugation of alertar is on its own page.
Related links
- Full conjugation of alertar — every tense and mood, with the complete tables.
- alertar examples and quiz — more sentences, dialogues and a longer quiz.
- Spanish Present tense guide — how the present tense works for all Spanish verbs.
- Spanish verbs — the full list of Spanish verbs on VerbFlow.
- Alegar conjugation — another -ar verb to compare with alertar.
- Alojar conjugation — another -ar verb to compare with alertar.
- Alarmar conjugation — another -ar verb to compare with alertar.
- Present Tense Conjugator — practise this verb in the interactive tool.
- Spanish Verb Quiz — test yourself on Spanish verbs.