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Pretérito de ser:

fui, fuiste, fue, fuimos, fuisteis, fueron

Pretérito de ir:

fui, fuiste, fue, fuimos, fuisteis, fueron

¿Cómo han evolucionado los verbos "ser" e "ir" para tener la misma conjugación en el pretérito (y también en el imperfecto y el futuro de subjuntivo)? ¿Y por qué las formas en el pretérito empiezan por "fu-"?


Preterit of ser:

fui, fuiste, fue, fuimos, fuisteis, fueron

Pretrit of ir:

fui, fuiste, fue, fuimos, fuisteis, fueron

How did the verbs ser and ir evolve to have the same conjugation in the preterit (and also in the imperfect and future subjunctive)? And why do their forms in preterit begin with fu-?

share|improve this question
I'm not sure if this in an example of "suppletion" or an example of the opposite of suppletion \-: There's probably a good question for the linguistics site in it though! – hippietrail Nov 16 '11 at 18:07
I am editing this question to be entirely in English, instead of a mix of Spanish and English. If you believe an exception should be made for this question, please weigh in on the meta discussion about this (and similar posts): – Flimzy Nov 26 '11 at 17:38
Portuguese follows the same pattern – andrerpena Feb 9 '12 at 15:19
up vote 12 down vote accepted


Lo he oído explicado así:

El pretérito de "ser" viene de la versión del latín de esse, que usa la raíz 'fui'.

La historia va de que "ir" es irregular en el sentido de que estaba compuesto de múltiples verbos, y por tanto toma su pretérito del latín "esse".

  • El presente, pretérito, subjuntivo del latín vadere.
  • El infinitivo del latín ire.
  • El condicional y el futuro vienen del infinitivo.


I've heard it explained this way:

The preterite of ser is from the latin version of esse, which uses the 'fui' root

The story goes that ir is irregular in the sense it was composed of multiple verbs, and therefore borrows its preterite form from the latin esse.

  • Present, preterite, subjunctive from Latin vadere.
  • Infinitive from Latin ire.
  • Conditional and future are from infinitive.
share|improve this answer
Ah yes well the composition of ir from multiple verbs is definitely a case of suppletion. The use of some forms in multiple verbs is something I'm not sure there's a term for. – hippietrail Nov 16 '11 at 18:11
I think the second link (vadere) is wrong - I get the conjugation table of the verb videre (to see). – kodkod Nov 22 '11 at 16:30
The preterite of ser is from the latin version of esse, which uses the 'fui' root You are just restating the presupposition from the question. – Cayetano Gonçalves Feb 10 '12 at 23:11
Although it is all true, it is not an answer to the original question. It is just the same said in different wording. – Honza Zidek May 15 at 11:15

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