alterar Preterite Conjugation
alterar — to change
The preterite of alter is regular: alteré, alteraste, alteró, alteramos, alterasteis, alteraron.
alterar Preterite Forms
When to Use the Preterite
Use the preterite of 'alterar' to talk about a specific, completed change in the past. For example, 'Alteró el diseño' means 'He/She/You (formal) changed the design' at a particular moment or over a defined period.
Notes on alterar in the Preterite
Alter is fully regular in the preterite tense. All endings follow the standard pattern for -ar verbs.
Example Sentences
Alteré las especificaciones del proyecto.
I changed the project specifications.
yo
¿Alteraste la configuración del sistema?
Did you change the system configuration?
tú
El gobierno alteró las leyes fiscales.
The government changed the tax laws.
él/ella/usted
Alteramos el orden de las tareas.
We changed the order of the tasks.
nosotros
Alteraron el curso de la conversación.
They changed the course of the conversation.
ellos/ellas/ustedes
Common Mistakes
Mistake: Using the imperfect instead of the preterite for a completed change.
Correct: Use 'alteró' for a specific change, not 'alteraba'.
Why: The preterite marks a completed action, while the imperfect describes an ongoing or habitual past action.
Mistake: Forgetting the accent on 'alteró' (él/ella/usted) and 'alteré' (yo).
Correct: The forms 'alteró' and 'alteré' require an accent mark on the final vowel.
Why: The accent mark indicates the stressed syllable and distinguishes these forms from other similar-looking verb forms.
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Related Tenses
Present
yo: altero
The present tense of alter (altero, alteras, altera, alteramos, alteráis, alteran) describes current actions, habits, or general truths.
Imperfect
yo: alteraba
The imperfect of alter (alteraba, alterabas, alteraba, alterábamos, alterabais, alteraban) describes ongoing or habitual past actions.
Future
yo: alteraré
The future tense of alter (alteraré, alterarás, alterará, alteraremos, alteraréis, alterarán) indicates actions that will happen.
Conditional
yo: alteraría
The conditional of alter (alteraría, alterarías, alteraría, alteraríamos, alteraríais, alterarían) expresses hypotheticals ('would') and polite requests.
Present Subjunctive
yo: altere
The present subjunctive of alter (altere, alteres, alteremos, alteréis, alteren) is used after expressions of will, doubt, emotion, and uncertainty.
Imperfect Subjunctive
yo: alterara
The imperfect subjunctive of alter (alterara/alterase) is used for past hypotheticals, wishes, or polite requests.
Affirmative Imperative
yo: altera
Alter commands are mostly regular: ¡altera, altere, alteremos, alterad, alteren!
Negative Imperative
yo: no alteres
Negative commands for alter are formed with 'no' + present subjunctive: no alteres, no altere, no alteremos, no alteréis, no alteren.