interferir Preterite Conjugation
interferir — to interfere
Interferir has a third-person stem change (e -> i) in the preterite: interfirió and interfirieron.
interferir Preterite Forms
When to Use the Preterite
Use the preterite to describe a specific instance in the past where someone or something blocked or interrupted an action.
Notes on interferir in the Preterite
It follows the pattern of -ir verbs that change e -> i in the third person (singular and plural). The other forms are regular.
Example Sentences
El ruido interfirió con mi sueño anoche.
The noise interfered with my sleep last night.
él/ella/usted
Ellos interfirieron en la votación final.
They interfered in the final vote.
ellos/ellas/ustedes
Interferí lo menos posible durante la reunión.
I interfered as little as possible during the meeting.
yo
Common Mistakes
Mistake: Él interfirió.
Correct: Él interfirió (with the i change).
Why: Learners often forget the e -> i stem change in the third-person preterite for this verb type.
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Related Tenses
Present
yo: interfiero
Interferir is a stem-changing verb in the present tense (e -> ie), except for nosotros and vosotros.
Imperfect
yo: interfería
Interferir is completely regular in the imperfect: interfería, interferías, interfería...
Future
yo: interferiré
Interferir is regular in the future; simply add endings to the infinitive.
Conditional
yo: interferiría
The conditional of interferir is regular: interferiría, interferirías, etc.
Present Subjunctive
yo: interfiera
Interferir has a stem change (ie) and a special nosotros/vosotros change (i) in the subjunctive.
Imperfect Subjunctive
yo: interfiriera
The imperfect subjunctive uses the 'interfir-' stem for all forms (interfiriera, interfirieras).
Affirmative Imperative
yo: interfiere
Use 'interfiere' to tell someone to step in, or 'interfiera' for formal requests.
Negative Imperative
yo: no interfieras
The negative imperative always uses the present subjunctive forms: no interfieras, no interfiera.