Influir: Full Conjugation

Influir means "to influence" and belongs to the family of -uir verbs (excluding -guir and -quir, which follow different rules). These verbs share a distinctive feature: a y is inserted before vowel endings a, e, o in many present-tense forms, because the Spanish ear can't comfortably handle two weak vowels in a row without it.

Other common verbs in this family include construir ("to build"), destruir ("to destroy"), huir ("to flee"), concluir ("to conclude"), and contribuir ("to contribute"). Learn one and you essentially know them all.

Present Indicative

Notice the y in every form except nosotros, which keeps the plain i because the ending -imos already contains a strong vowel after the stem.

Preterite

The third-person forms (influyó, influyeron) take a y, because an i between two vowels would otherwise become silent or awkward.

Imperfect

The imperfect is regular — no y needed, because the endings start with í, which carries its own stress and doesn't collapse.

Future

Conditional

Present Subjunctive

All six subjunctive forms take a y, including nosotros, because every ending now starts with a.

Imperfect Subjunctive (-ra forms)

Imperative

Non-Finite Forms

• Infinitive: influir
• Gerund: influyendo
• Past participle: influido

The gerund also takes a y (influyendo), following the same rule: the ending -iendo would otherwise produce a collapsed, difficult-to-pronounce -iiendo.

Common Uses

Influir typically takes the preposition en before its object: influir en alguien, influir en una decisión. It can also take sobre in more formal contexts: influir sobre la opinión pública. The noun form is influencia, and the common adjective is influyente ("influential").