alterar Present Subjunctive Conjugation
alterar — to change
The present subjunctive of alter (altere, alteres, alteremos, alteréis, alteren) is used after expressions of will, doubt, emotion, and uncertainty.
alterar Present Subjunctive Forms
When to Use the Present Subjunctive
Whenever you express a wish, a doubt, an emotion, or something uncertain, you'll likely need the present subjunctive. For example, 'Espero que alteres tu horario' (I hope you change your schedule) or 'Dudo que alteren las reglas' (I doubt they will change the rules).
Notes on alterar in the Present Subjunctive
Alter is regular in the present subjunctive. The forms are derived from the 'yo' form of the present indicative ('altero'), dropping the -o and adding the opposite vowel endings (-e for -ar verbs).
Example Sentences
Espero que alteres tu forma de pensar.
I hope you change your way of thinking.
tú
Quiero que usted altere el documento.
I want you to change the document.
No creemos que ellos alteren el plan.
We don't believe they will alter the plan.
ellos/ellas/ustedes
Es importante que alteremos la estrategia.
It's important that we change the strategy.
nosotros
Dudo que alteréis la decisión.
I doubt you all will change the decision.
vosotros
Common Mistakes
Mistake: Using the present indicative instead of the present subjunctive.
Correct: Use 'alteres' after 'espero que', not 'alteras'.
Why: Expressions of hope, doubt, and desire trigger the subjunctive mood, not the indicative.
Mistake: Forgetting the 'que'.
Correct: The subjunctive clause is usually introduced by 'que': 'Espero que alteres...'.
Why: The conjunction 'que' connects the main clause (expressing the emotion/doubt) to the subordinate clause in the subjunctive.
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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.
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.
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.