Preterite — irregular verbs

A large group of common Spanish verbs forms the preterite not by adding the regular endings to the infinitive stem, but by using a completely different, irregular stem with its own set of unstressed endings. Additionally, the verbs ser and ir share an identical set of preterite forms, and the verbs ver and dar have short preterite forms that carry no written accent. These irregularities must be memorised individually.

Use the preterite — regular or irregular — whenever you describe a completed action or event in the past. The irregular forms covered here apply in exactly the same contexts as regular preterites:

• A single completed action — something that happened once and is finished: «Ayer hice la tarea.» (Yesterday I did the homework.)

• A sequence of past events — actions that followed one after another: «Vi la película y luego le di mi opinión.»

• A past state with a clear beginning or end — «Estuve en casa toda la tarde.» (I was at home all afternoon.)

Verbs with irregular preterite stems use a shared set of endings that differ from both the regular -ar and regular -er/-ir endings. The key feature is that the first- and third-person singular endings are unstressed and carry no written accent (unlike regular preterites, where -é and -ó carry a tilde).

Irregular-stem endings (used by tener, hacer, estar, and others):

The three main irregular verbs at this level are tener (stem tuv-), hacer (stem hic-, but hiz- before -o), and estar (stem estuv-).

Ser and ir share identical preterite forms. Context makes the meaning clear.

Ver and dar have short preterite forms. Because the first- and third-person singular are monosyllables (vi, vio, di, dio), they take no written accent according to standard Spanish orthography.

• Regularising the irregular stem. Learners sometimes apply the regular -ar or -er/-ir endings directly to the infinitive stem, producing «*hací» or «*tení». These verbs abandon their infinitive stem entirely in the preterite: the correct forms are hice and tuve.

• Adding a written accent to dio and vio. Writing «*dió» or «*vió» is incorrect. Spanish orthographic rules do not place a tilde on monosyllables unless it is needed to distinguish two words. The correct forms are dio and vio (no accent).

• Grafting a regular ending onto an irregular stem. Some learners correctly identify the irregular stem but then add the regular third-person ending, producing «*tuvió» or «*hizió». Irregular-stem verbs use the unstressed ending -o (not -ió) for the third-person singular. The correct forms are tuvo and hizo.