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 |
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 |
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.