Spanish irregular preterite verbs: the stems to memorize

Short answer: most irregular preterites follow one pattern — a new stem plus -e, -iste, -o, -imos, -isteis, -ieron, with no written accents. Learn the stem and the whole tense comes for free.

The “strong” stems

The -j stems (third-person plural ends in -eron)

The special cases

Stem changes and spelling changes

-ir stem-changing verbs change only in the third person: pedir → pidió, pidieron; dormir → durmió, durmieron. Spelling changes keep the sound: buscar → busqué, llegar → llegué, empezar → empecé, leer → leyó.

Seeing the irregular part helps

Verbizo underlines and colours exactly the letters that break the pattern (tuve, hizo, dijeron), and its Irregular deck drills only these verbs.

FAQ

Why is it “tuve” and not “tuvé”?

Irregular preterite stems take endings with no written accent: tuve, tuvo, hice, hizo, pude, pudo.

Why is it “dijeron” and not “dijieron”?

Stems ending in -j drop the i in the third-person plural: dijeron, trajeron, condujeron, produjeron.

Are ser and ir really the same in the preterite?

Yes: fui, fuiste, fue, fuimos, fuisteis, fueron. Context tells you whether it means “was” or “went”.

Drill irregular forms with highlights: Verbizo (Google Play)

← See Verbizo: Spanish verbs in every tense