Alterar Present Tense Conjugation in Spanish
The present tense of alterar — “to alter, to disturb” 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 alterar 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. Alterar means to alter or to disturb, to change something from its normal state, such as plans, order or someone's calm. It is a fully regular verb used in everyday life, work and medicine. To see it in a real sentence: Altero los planes del viaje. — “I alter the travel plans.” Learn the six forms in the table below, and the present tense of alterar will be ready for everyday conversation.
Present tense conjugation table: alterar
Every person of alterar in the present tense. The gerund is alterando and the past participle is alterado.
Present indicative
| Person | Form |
|---|---|
| yo | altero |
| tú | alteras |
| él/ella/Ud. | altera |
| nosotros/as | alteramos |
| vosotros/as | alteráis |
| ellos/ellas/Uds. | alteran |
How the present indicative of alterar is formed
The present indicative of alterar 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 | altero |
| tú | -as | alteras |
| él/ella/Ud. | -a | altera |
| nosotros/as | -amos | alteramos |
| vosotros/as | -áis | alteráis |
| ellos/ellas/Uds. | -an | alteran |
Alterar is a regular -ar verb in the present tense, so the table above is completely regular. The stem is alter- 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 alterar is alterando and the past participle is alterado. 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 alterar
The present tense is not one single use — it covers several situations, and alterar 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 alterar fits naturally into daily life.
“Yo altero los planes del viaje todos los días.” — “I alter the travel plans 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 altera el orden de la casa.” — “He/she alters the order of the house.”
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 altero can mean both “I alter” and “I am altering”.
“Ahora mismo, yo altero la calma del barrio.” — “Right now, I alter the calm of the neighbourhood.”
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 altero el resultado del análisis.” — “Tomorrow, I will alter the result of the test.”
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 alteras los planes del viaje?” — “Do you alter the travel plans?”
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: Altera el orden de la casa. — “He/she alters the order of the house.”
- Preterite — one finished occasion: Alteró el orden de la casa. — 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: Alteran la calma del barrio. — “They alter the calm of the neighbourhood.”
- Imperfect — a past habit or background: Alteraban la calma del barrio. — 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: Alteras el resultado del análisis. — “You alter the result of the test.”
- Future — what will happen: Alterarás el resultado del análisis. — the same idea, placed in the future.
Examples: alterar in the present tense
Seven sentences that show alterar in the present tense only, across all six persons. Read each one aloud, notice the ending, and check the translation.
- Yo altero los planes del viaje. — “I alter the travel plans.”
- Tú alteras el orden de la casa. — “You alter the order of the house.”
- Él altera la calma del barrio. — “He alters the calm of the neighbourhood.”
- Nosotros alteramos el resultado del análisis. — “We alter the result of the test.”
- Vosotros alteráis los planes del viaje. — “You (plural) alter the travel plans.”
- Ellos alteran el orden de la casa. — “They alter the order of the house.”
- ¿Tú alteras la calma del barrio? — “Do you alter the calm of the neighbourhood?”
Common mistakes with alterar in the present tense
These are the errors learners actually make with alterar in the present tense. Each one shows the wrong form, the right form, and why the right form is right.
✗ Yo alterar los planes del viaje. (using the infinitive instead of a conjugated form).
✓ Correct: Yo altero los planes del viaje.
The infinitive is not a conjugated form. With yo, the present tense of alterar is altero, not the infinitive alterar.
✗ Vosotros alterais los planes del viaje. (forgetting the accent on the vosotros form).
✓ Correct: Vosotros alteráis los planes del viaje.
The vosotros present form carries a written accent: alteráis, not alterais. The accent marks the stressed vowel, and leaving it out is a spelling mistake.
✗ Ayer, yo altero el orden de la casa. (using the present for a finished past action).
✓ Correct: Ayer, yo alteré el orden de la casa.
The present and the preterite are different tenses: altero is happening now, while alteré is a finished action in the past. Use the preterite with ayer.
✗ Treating alterar and cambiar as identical in every context. (confusing alterar with cambiar).
✓ Correct: Alterar means to alter, to disturb, while cambiar means to change.
They overlap, but each has uses the other does not: alterar fits sentences such as Altero los planes del viaje, while cambiar belongs in a different sentence. Check the meaning you want before choosing.
Quiz: alterar in the present tense
Eight questions on the present tense of alterar. 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 alterar for tú?
- a) alteras
- b) altero
- c) altera
- d) alteran
2. Complete the sentence: Yo ______ los planes del viaje. — “I alter the travel plans.”
- a) altera
- b) alteramos
- c) alteras
- d) altero
3. Complete the sentence: Él ______ el orden de la casa. — “He/she alters the order of the house.” (present tense)
- a) alteraba
- b) alterará
- c) altera
- d) alteró
4. Which is the correct present tense form of alterar for nosotros?
- a) alteran
- b) alteramos
- c) altero
- d) altera
5. Which sentence uses alterar correctly in the present tense?
- a) Él alteró el orden de la casa.
- b) Él altera el orden de la casa.
- c) Él alterará el orden de la casa.
- d) Ellos altera el orden de la casa.
6. Complete the sentence: Ellos ______ la calma del barrio. — “They alter the calm of the neighbourhood.”
- a) altero
- b) altera
- c) alteramos
- d) alteran
7. Complete the question: ¿Tú ______ el resultado del análisis? — “Do you alter the result of the test?”
- a) altera
- b) alterarás
- c) alteras
- d) altero
8. What is the gerund of alterar?
- a) alteré
- b) alterando
- c) alterado
- d) altero
Answer key
a) alteras — The tú form is alteras. The -s ending belongs to tú in the present; altero is yo, altera is él/ella and alteran is ellos/ellas.
d) altero — The sentence needs the yo form in the present: altero. The other options are the wrong person.
c) altera — The sentence needs the él/ella/Ud. form in the present: altera. The other options are the preterite, the imperfect and the future.
b) alteramos — Nosotros takes alteramos. In the present the nosotros ending for -ar verbs is -amos, attached to the stem.
b) Él altera el orden de la casa. — Él altera el orden de la casa. is correct: the verb agrees with its subject. The other sentences use the wrong person or the wrong tense.
d) alteran — The subject is ellos/ellas/Uds., so the present form is alteran.
c) alteras — The question needs the tú form in the present: alteras.
b) alterando — The gerund is alterando. It is the form you use with estar for the progressive (estar + gerund), and it is not the past participle alterado.
Frequently asked questions
Is alterar regular in the present tense?
Yes. Alterar is a regular -ar verb in the present tense, so the forms follow the standard endings: altero, alteras, altera, alteramos, alteráis and alteran.
What is the gerund and the past participle of alterar?
The gerund is alterando and the past participle is alterado. Use the gerund with estar for the progressive, and the participle with haber for the perfect tenses.
How do you say “I alter” in Spanish?
Say altero. For example: Altero los planes del viaje. — “I alter the travel plans.”
What is the difference between alterar and cambiar?
Alterar means “to alter, to disturb”, while cambiar means “to change”. They are related words that learners often meet together, but they are not interchangeable — use alterar when you mean “to alter, to disturb” and cambiar when you mean “to change”. The full conjugation of alterar is on its own page.
Related links
- Full conjugation of alterar — every tense and mood, with the complete tables.
- alterar 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.
- Alojar conjugation — another -ar verb to compare with alterar.
- Alertar conjugation — another -ar verb to compare with alterar.
- Alumbrar conjugation — another -ar verb to compare with alterar.
- Present Tense Conjugator — practise this verb in the interactive tool.
- Spanish Verb Quiz — test yourself on Spanish verbs.