J-Stem Irregulars (Decir, Traer, -Ducir Verbs)

The final family of preterite irregulars uses a j-stem. Like the u-stem and i-stem groups, these verbs take unaccented endings — but with one important difference in the ellos/ellas/ustedes form.

The shared endings

SubjectEnding
yo-e
-iste
él / ella / usted-o
nosotros-imos
ellos / ellas / ustedes-eron
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The ellos ending is -eron, not -ieron. The i is dropped after j. So it's dijeron, not dijieron. This is the single most important thing to remember about j-stem verbs.

The j-stems

InfinitiveJ-Stem
decirdij-
traertraj-
conducirconduj-
producirproduj-
traducirtraduj-

In general, any verb ending in -ducir follows this pattern.

Decir (to say, to tell)

SubjectForm
yodije
dijiste
él / ella / usteddijo
nosotrosdijimos
ellos / ellas / ustedesdijeron

Me dijo la verdad al final.

He told me the truth in the end.

Nos dijeron que el vuelo estaba retrasado.

They told us that the flight was delayed.

Traer (to bring)

SubjectForm
yotraje
trajiste
él / ella / ustedtrajo
nosotrostrajimos
ellos / ellas / ustedestrajeron

Traje un regalo para tu cumpleaños.

I brought a gift for your birthday.

Trajeron flores y chocolates.

They brought flowers and chocolates.

Conducir (to drive)

SubjectForm
yoconduje
condujiste
él / ella / ustedcondujo
nosotroscondujimos
ellos / ellas / ustedescondujeron

Condujimos toda la noche hasta Monterrey.

We drove all night to Monterrey.

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In much of Latin America, manejar is more common than conducir for "to drive" in everyday speech, but conducir is still perfectly correct and is the usual verb in Spain and in formal writing.

Producir (to produce)

SubjectForm
yoproduje
produjiste
él / ella / ustedprodujo
nosotrosprodujimos
ellos / ellas / ustedesprodujeron

La fábrica produjo mil unidades el año pasado.

The factory produced a thousand units last year.

Traducir (to translate)

SubjectForm
yotraduje
tradujiste
él / ella / ustedtradujo
nosotrostradujimos
ellos / ellas / ustedestradujeron

Traduje el documento al inglés.

I translated the document into English.

Why -eron and not -ieron?

Historically, an unstressed i between certain consonants simply disappeared in Spanish. After a j, an i sounded redundant — the j already carries a bit of that y-like quality — so speakers dropped it. The result is the clean -eron ending you see in dijeron, trajeron, and condujeron.

Compare: comieron (regular) vs. dijeron (j-stem). The difference is just that missing i.

Common mistakes

❌ Ellos dijieron la verdad.

Wrong: after j, the i in -ieron is dropped.

✅ Ellos dijeron la verdad.

Correct: j-stem verbs use -eron, not -ieron.

❌ Yo dició algo importante.

Wrong: decir uses the j-stem dij-, not dic-.

✅ Yo dije algo importante.

Correct: dije uses the j-stem with the unaccented ending -e.

❌ Ella trajó un regalo.

Wrong: irregular preterites have no accent on the él/ella form.

✅ Ella trajo un regalo.

Correct: trajo — no accent, stress on the stem.

❌ Yo conducí toda la noche.

Wrong: conducir uses the j-stem conduj-, not conduc-.

✅ Yo conduje toda la noche.

Correct: conduje uses the j-stem with the unaccented ending -e.

With the u-stem, i-stem, and j-stem families covered, you now have a map of every preterite irregular you are likely to meet. From here, the rest of this subgroup focuses on usagewhen and why to reach for the preterite rather than another past tense.

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