Influir — "to influence, to have an effect on, to bear on" — is a -uir verb that English speakers reach for constantly and almost always conjure incorrectly the first time. The morphology is shared with all the other -uir verbs (huir, incluir, construir, contribuir, distribuir, destruir, atribuir, concluir, excluir, intuir, instruir, fluir, sustituir): a y appears between stem and ending whenever the ending starts with a vowel other than i. So you get influyo, influye, influyen, influyó, influyeron, influyendo, influya — and on the other side, influimos, influis, influí, influido, influiré.
What sets influir apart from its English cousin and requires its own dedicated discussion is the obligatory preposition en. Where English happily says she influences her sister — a transitive verb with a direct object — Spanish requires influye *en su hermana. There is no transitive *influir in standard Spanish. Drop the en and the sentence is ungrammatical.
Non-finite forms
| Form | Spanish | English |
|---|---|---|
| Infinitivo | influir | to influence, to bear on |
| Infinitivo compuesto | haber influido | to have influenced |
| Gerundio | influyendo | influencing |
| Gerundio compuesto | habiendo influido | having influenced |
| Participio | influido (regular) | influenced |
Note: there is a separate adjective influyente (influential) — un escritor muy influyente (a very influential writer). Don't confuse the adjective with the gerund: influyente is an -nte adjective derived from the present participle, influyendo is the gerund used in progressive constructions.
Indicative — simple tenses
Presente
| yo | tú | él/ella/usted | nosotros | vosotros | ellos/ellas/ustedes |
|---|---|---|---|---|---|
| influyo | influyes | influye | influimos | influis | influyen |
The y appears in yo, tú, él, ellos — every form whose ending begins with a vowel other than i. The vosotros form influis follows the 2010 RAE rule and is now written without an accent (older texts may show influís).
La música que escuchas de adolescente influye mucho en tus gustos adultos.
The music you listen to as a teenager has a big influence on your adult taste.
El clima de la zona influye directamente en la calidad del vino que se produce.
The local climate directly affects the quality of the wine produced.
Pretérito perfecto simple
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| influí | influiste | influyó | influimos | influisteis | influyeron |
The yo form influí requires its written accent (same rule as huí, incluí, caí). The third-person influyó and influyeron show the standard i → y conversion between vowels.
Mi profesora de literatura influyó muchísimo en mi decisión de estudiar Filología.
My literature teacher had a huge influence on my decision to study philology.
Las decisiones de Felipe II influyeron en el rumbo de la historia europea durante décadas.
Philip II's decisions shaped the course of European history for decades.
Pretérito imperfecto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| influía | influías | influía | influíamos | influíais | influían |
Regular -ir imperfect endings. All forms accent the í.
De pequeña, lo que me decían mis hermanos mayores influía en todo lo que hacía.
As a little girl, what my older siblings told me affected everything I did.
Futuro simple
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| influiré | influirás | influirá | influiremos | influiréis | influirán |
Future built on the full infinitive influir-. No y in any form.
Esta crisis influirá en la economía durante muchos años, no nos engañemos.
This crisis will affect the economy for many years — let's not kid ourselves.
Condicional
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| influiría | influirías | influiría | influiríamos | influiríais | influirían |
No pensé que mi opinión influiría tanto en su decisión final.
I didn't think my opinion would carry so much weight in her final decision.
Indicative — compound tenses
All compound tenses pair haber with the regular participle influido. The participle keeps the i — no y conversion.
Pretérito perfecto compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| he influido | has influido | ha influido | hemos influido | habéis influido | han influido |
Esta semana ha influido en mi humor el cambio de hora, no me adapto.
The time change has affected my mood this week — I just can't adjust.
Pretérito pluscuamperfecto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| había influido | habías influido | había influido | habíamos influido | habíais influido | habían influido |
Para cuando se publicó el libro, su filosofía ya había influido en toda una generación.
By the time the book came out, his philosophy had already influenced an entire generation.
Futuro compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| habré influido | habrás influido | habrá influido | habremos influido | habréis influido | habrán influido |
Condicional compuesto
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| habría influido | habrías influido | habría influido | habríamos influido | habríais influido | habrían influido |
De haber sabido cuánto le habría influido aquel comentario, no lo habría hecho.
Had I known how much that comment would have affected him, I wouldn't have made it.
Subjunctive — simple tenses
Presente de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| influya | influyas | influya | influyamos | influyáis | influyan |
Every form takes y — all endings begin with -a. The vosotros form influyáis carries the obligatory accent.
No dejes que tus miedos influyan en una decisión tan importante.
Don't let your fears affect such an important decision.
Es normal que la opinión de la familia influya en estas cosas.
It's normal for family opinion to weigh in on these matters.
Imperfecto de subjuntivo (-ra / -se)
| yo | tú | él | nosotros | vosotros | ellos | |
|---|---|---|---|---|---|---|
| -ra | influyera | influyeras | influyera | influyéramos | influyerais | influyeran |
| -se | influyese | influyeses | influyese | influyésemos | influyeseis | influyesen |
Built on the influy- stem of the third-person preterite. Every form takes y. -Ra dominates spoken Spain; -se is more formal/literary.
Si la prensa no influyera tanto en la opinión pública, todo sería diferente.
If the press didn't influence public opinion so much, everything would be different.
Subjunctive — compound tenses
Pretérito perfecto de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos |
|---|---|---|---|---|---|
| haya influido | hayas influido | haya influido | hayamos influido | hayáis influido | hayan influido |
No me sorprende que haya influido tanto en sus alumnos: es una profesora excepcional.
I'm not surprised she's had such an impact on her students — she's an exceptional teacher.
Pluscuamperfecto de subjuntivo
| yo | tú | él | nosotros | vosotros | ellos | |
|---|---|---|---|---|---|---|
| -ra | hubiera influido | hubieras influido | hubiera influido | hubiéramos influido | hubierais influido | hubieran influido |
| -se | hubiese influido | hubieses influido | hubiese influido | hubiésemos influido | hubieseis influido | hubiesen influido |
Si hubieras influido un poco más en él de joven, ahora no estaría así.
If you'd had a bit more influence on him when he was young, he wouldn't be like this now.
Imperative
| Form | Affirmative | Negative |
|---|---|---|
| tú | influye | no influyas |
| usted | influya | no influya |
| nosotros | influyamos | no influyamos |
| vosotros | influid | no influyáis |
| ustedes | influyan | no influyan |
In practice imperatives of influir are rare — you don't normally command someone to influence somebody. The form that does come up is the negative no influyas en (don't influence): No influyas en su decisión, No influyáis en los niños con vuestros prejuicios.
No influyas en su decisión: que elija libremente.
Don't influence her decision — let her choose freely.
No influyáis en los niños con vuestras manías.
Don't influence the children with your hangups.
The obligatory en: influir EN
This is the syntactic point that justifies the entire page. Spanish influir is intransitive — it does not take a direct object. To name the thing influenced you need a preposition, and the standard preposition is en:
- La luna influye en las mareas. — The moon influences the tides.
- Tu opinión influye en mi decisión. — Your opinion influences my decision.
- Lo que dijiste influyó en su comportamiento. — What you said influenced her behaviour.
There is a literary/formal alternative, influir sobre, with essentially the same meaning:
- La filosofía clásica influyó sobre el pensamiento renacentista. — Classical philosophy influenced Renaissance thought.
In everyday peninsular Spanish, en is the unmarked choice. Sobre feels markedly more formal or academic, and is more common in writing about history, philosophy, art, or politics. The two are rarely felt as different in meaning — they are register variants.
What you cannot do is drop the preposition entirely:
- ❌ La luna influye las mareas.
- ❌ Tu opinión influye mi decisión.
- ❌ Lo que dijiste influyó su comportamiento.
All three are ungrammatical. This is the single most common error English speakers make with influir.
Why this matters: the structural difference from English
English influence is transitive — the thing influenced is its direct object. Spanish historically reanalyzed the verb as expressing a flowing-in-on relationship (the Latin influere literally meant "to flow into"), which Spanish makes explicit through en. So Spanish says, structurally, "her opinion flows into my decision," while English collapses the relation into a bare transitive verb. The result: every English-to-Spanish translation must insert en.
A related verb worth knowing is afectar (to affect), which is transitive in Spanish and so behaves more like English affect: La crisis afecta a la economía (the crisis affects the economy — note the personal a before la economía, but no en). When English affect and influence both fit, Spanish typically uses afectar for direct, often negative, effects and influir en for influence over time or shaping of decisions.
El alcohol influye en el tiempo de reacción más de lo que la gente piensa.
Alcohol affects reaction time more than people think.
Las teorías de Freud influyeron sobre toda la psicología del siglo XX.
Freud's theories influenced all of twentieth-century psychology.
Influir, influencia, influyente, influencer
A note on the noun family. The standard noun is influencia (influence): tener mucha influencia (to have a lot of influence). The adjective is influyente (influential): un político muy influyente. There is also a verb influenciar (to influence) used in some varieties of Spanish, but the RAE marks it as redundant — modern educated Spain prefers influir en. Influenciar is much more common in Latin America.
The borrowed English noun influencer (with English pronunciation) is now ubiquitous in Spanish social-media talk: los influencers de Instagram, una influencer de moda. The RAE has tried to push the calque influidor/influidora, but it has not caught on.
High-frequency collocations from peninsular Spanish
| Phrase | Translation |
|---|---|
| influir en una decisión | to influence a decision |
| influir en alguien | to have an influence on someone |
| influir sobre algo | to bear on something (formal) |
| influir negativamente / positivamente | to have a negative / positive effect |
| dejarse influir | to let oneself be influenced, to be easily swayed |
| tener influencia | to have influence, to have clout |
| tráfico de influencias | (legal/political) influence-peddling |
| bajo la influencia de | under the influence of |
Dejarse influir is the standard way to talk about being easily swayed: No te dejes influir por lo que diga la gente (Don't let yourself be influenced by what people say). Tráfico de influencias is the technical Spanish legal term for the crime English calls influence-peddling, and it appears constantly in news coverage of corruption cases.
No te dejes influir por lo que diga la gente, tú haz lo que sientas.
Don't let yourself be swayed by what people say — do what you feel is right.
Lo han imputado por tráfico de influencias y prevaricación.
They've charged him with influence-peddling and malfeasance.
The classic English-speaker error: dropping en
By far the most common error is mapping English transitive influence onto a bare transitive influir:
- ❌ Sus amigos influyen su comportamiento. (His friends influence his behaviour.)
- ✅ Sus amigos influyen en su comportamiento.
A second error is the morphological one shared with all -uir verbs: producing influo, influe, influeron, influiendo instead of influyo, influye, influyeron, influyendo. The fix is the same as for huir and incluir: internalise the y-insertion rule.
A third error, more subtle: using afectar when influir is wanted, or vice versa. Rough heuristic: afectar is for direct, often immediate, often negative effects (El humo me afecta a los ojos — the smoke affects my eyes); influir is for shaping, swaying, gradual effects (Su opinión influyó en mi decisión — her opinion shaped my decision). When in doubt, influir en is the safer choice for "influence" in the sense of swaying or shaping.
Common Mistakes
❌ Su madre influye sus decisiones.
Influir is intransitive — it requires en (or, more formally, sobre). 'Su madre influye en sus decisiones.'
✅ Su madre influye en sus decisiones.
His mother influences his decisions.
❌ El cansancio inflúe en mi rendimiento.
The third-person present is influye, not inflúe — the y replaces the i and there is no accent. The accent appears only on the yo preterite (influí).
✅ El cansancio influye en mi rendimiento.
Tiredness affects my performance.
❌ Está influiendo en mi humor.
The gerund needs the i→y conversion between vowels: influyendo, not influiendo.
✅ Está influyendo en mi humor.
It's affecting my mood.
❌ Aquella conversación influyó a mi vida entera.
Influir takes en, not a. The preposition a goes with afectar (afectó a mi vida), not influir.
✅ Aquella conversación influyó en mi vida entera.
That conversation influenced my whole life.
❌ Mis amigos siempre me influencian para mal.
Influenciar exists but is marked as redundant by the RAE and sounds Latin American. In peninsular Spanish prefer 'me influyen para mal' or 'son una mala influencia para mí.'
✅ Mis amigos siempre me influyen para mal.
My friends always influence me for the worse.
Key Takeaways
- Influir follows the standard -uir orthographic pattern: insert y between stem and ending whenever the ending begins with a vowel other than i; convert unstressed i between vowels to y. Same paradigm as huir, incluir, construir.
- Forms with y: influyo, influyes, influye, influyen, influya, influyas, influya, influyamos, influyáis, influyan, influyó, influyeron, influyendo, influyera/influyese (entire imperfect subjunctive).
- Forms without y: influimos, influis, influí, influiste, influimos, influisteis, influido, influía, influiré and the entire future and conditional.
- Influir is intransitive in Spanish. It requires the preposition en before what is influenced: influye en su hermana. A literary alternative is influir sobre.
- The yo preterite influí requires its written accent. The vosotros present influis follows the 2010 RAE rule and goes unaccented.
- Distinguish from afectar (transitive, takes personal a, for direct/immediate effects) and from the Latin American influenciar (redundant in peninsular usage).
- The noun family: influencia (influence), influyente (influential, adjective), and the borrowed influencer (which the RAE-proposed influidor has failed to dislodge).
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