alterar Imperfect Conjugation
alterar — to change
The imperfect of alter (alteraba, alterabas, alteraba, alterábamos, alterabais, alteraban) describes ongoing or habitual past actions.
alterar Imperfect Forms
When to Use the Imperfect
Use the imperfect of 'alterar' to describe a state or action that was happening over a period in the past, or a repeated action. For instance, 'El ruido alteraba mi concentración' (The noise was altering/used to alter my concentration). It sets the background scene.
Notes on alterar in the Imperfect
Alter is regular in the imperfect tense. The conjugation follows the standard pattern for -ar verbs.
Example Sentences
Cuando era niño, el mal tiempo a menudo alteraba mis planes.
When I was a child, bad weather often altered my plans.
yo
Tú alterabas el resultado sin darte cuenta.
You were changing the result without realizing it.
tú
Ella alteraba la receta para hacerla más picante.
She used to alter the recipe to make it spicier.
él/ella/usted
Nosotros alterábamos la rutina los domingos.
We used to change the routine on Sundays.
nosotros
Ellos alteraban el orden de las prioridades constantemente.
They were constantly changing the order of priorities.
ellos/ellas/ustedes
Common Mistakes
Mistake: Using the preterite instead of the imperfect for ongoing past actions.
Correct: Use 'alteraba' for something that was happening, not 'alteró'.
Why: The imperfect describes continuous or habitual past actions, whereas the preterite describes completed actions.
Mistake: Confusing 'alteraba' with 'alternaba'.
Correct: 'Alteraba' means changing/disturbing; 'alternaba' means alternating/taking turns.
Why: Similar sounds can lead to confusion between these two verbs.
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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.
Preterite
yo: alteré
The preterite of alter is regular: alteré, alteraste, alteró, alteramos, alterasteis, alteraron.
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.