Sp3 LP Pretérito vs Imperfecto — Comprehensive Study Notes

A collection of key vocabulary terms covering pretérito vs. imperfecto, regular and irregular verb patterns, and common stem-changing verbs for Spanish past tenses.

Pretérito (Past Tense)

A past tense used for completed actions, beginnings/ends, specific times/dates, and events in a sequence.

Imperfecto (Imperfect)

A past tense used for habitual or ongoing past actions, descriptions, and setting the scene.

Verbos regulares

Regular verbs in the pretérito follow standard endings for -AR, -ER, and -IR.

Verbos de chancla (Chancla verbs)

Some -IR verbs have stem changes only in certain pretérito forms (él/ella/usted and ellos/ellas/ustedes); changes are E→I or O→U.

E-I stem change (preto)

In pretérito, certain -IR verbs change E to I in affected forms (e.g., divertirse → se divirtió).

O-U stem change (preto)

In pretérito, certain -IR verbs change O to U in affected forms (e.g., dormir → durmieron).

Pedir

To ask for; an -IR verb with a pretérito stem change (pedí, pediste, pidió, pedimos, pedisteis, pidieron).

Ser (pretérito)

Ser and Ir share identical pretérito conjugations: fui, fuiste, fue, fuimos, fuisteis, fueron.

Ir (pretérito)

To go; shares the same pretérito forms as Ser (fui, fuiste, fue, fuimos, fuisteis, fueron).

Ser vs Ir (que tienen en común)

In pretérito, the conjugations of Ser and Ir are identical; context determines the meaning.

J-stem verbs

Preterite stems from -j- group: conducir, decir, traer, traducir; forms like conduje, dijiste, trajeron.

U-stem verbs

Preterite stems for estar, poder, poner, saber, tener; stems: estu-, pud-, pus-, sup-, tuv- (e.g., estuve, tuvieron).

I-stem verbs

Preterite stems for hacer, querer, venir; stems: hic-, quis-, vin- (e.g., hice, hizo, hicimos).

Saber (pretérito)

Meaning shifts from 'to know (information)' in present to 'to find out/learn' in pretérito.

Conocer (pretérito)

Meaning shifts from 'to know (someone)' in present to 'to meet (someone)' in pretérito.

Poder (pretérito)

Meaning shifts from 'to be able' in present to 'to manage/succeed (could and did)' in pretérito.

Querer (pretérito)

Meaning shifts from 'to want' in present to 'to try (to attempt)' in pretérito.

Imperfecto -AR endings

Endings for -AR in the imperfect: -aba, -abas, -aba, -ábamos, -abais, -aban.

Imperfecto -ER/-IR endings

Endings for -ER/-IR in the imperfect: -ía, -ías, -ía, -íamos, -íais, -ían.

Irregular imperfect verbs

Three verbs are irregular in the imperfect: ir, ser, y ver.

Ir (imperfect)

Imperfect forms: iba, ibas, iba, íbamos, ibais, iban.

Ser (imperfect)

Imperfect forms: era, eras, era, éramos, eran.

Ver (imperfect)

Imperfect forms: veía, veías, veía, veíamos, veían.

Interrupting actions (pretérito)

In a sentence, the interrupting action is in pretérito; the ongoing action is in imperfect (e.g., Justo cuando empezábamos a ser amigos, fue…).