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
| Subject | Ending |
|---|---|
| yo | -e |
| tú | -iste |
| él / ella / usted | -o |
| nosotros | -imos |
| ellos / ellas / ustedes | -eron |
The j-stems
| Infinitive | J-Stem |
|---|---|
| decir | dij- |
| traer | traj- |
| conducir | conduj- |
| producir | produj- |
| traducir | traduj- |
In general, any verb ending in -ducir follows this pattern.
Decir (to say, to tell)
| Subject | Form |
|---|---|
| yo | dije |
| tú | dijiste |
| él / ella / usted | dijo |
| nosotros | dijimos |
| ellos / ellas / ustedes | dijeron |
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)
| Subject | Form |
|---|---|
| yo | traje |
| tú | trajiste |
| él / ella / usted | trajo |
| nosotros | trajimos |
| ellos / ellas / ustedes | trajeron |
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)
| Subject | Form |
|---|---|
| yo | conduje |
| tú | condujiste |
| él / ella / usted | condujo |
| nosotros | condujimos |
| ellos / ellas / ustedes | condujeron |
Condujimos toda la noche hasta Monterrey.
We drove all night to Monterrey.
Producir (to produce)
| Subject | Form |
|---|---|
| yo | produje |
| tú | produjiste |
| él / ella / usted | produjo |
| nosotros | produjimos |
| ellos / ellas / ustedes | produjeron |
La fábrica produjo mil unidades el año pasado.
The factory produced a thousand units last year.
Traducir (to translate)
| Subject | Form |
|---|---|
| yo | traduje |
| tú | tradujiste |
| él / ella / usted | tradujo |
| nosotros | tradujimos |
| ellos / ellas / ustedes | tradujeron |
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 usage — when and why to reach for the preterite rather than another past tense.
Related Topics
- U-Stem Irregulars (Tener, Estar, Poder, Poner, Saber, Andar, Haber)B1 — A family of common verbs that share a u-stem and a single set of unaccented irregular endings in the preterite.
- I-Stem Irregulars (Hacer, Querer, Venir)B1 — Three high-frequency verbs that share an i-stem and the same unaccented endings as the u-stem group.
- Regular -er and -ir VerbsA2 — Regular -er and -ir verbs share one set of preterite endings: -í, -iste, -ió, -imos, -ieron.