Spanish Verbs: Preterite Stem Changing

Not all Spanish verbs act the same in the preterite tense. Below we'll explore special verbs whose stems changes in the preterite tense.

Present tense stem changing -ar and -er verbs in the preterite

-ar and -er verbs, such as entender and cerrar, whose stems change in the present tense do not change in the preterite tense. These present tense stem changing verbs are conjugated in the preterite tense just like other regular verbs. Read and listen to the following examples, then repeat each out loud.
Present Tense
Preterite Tense
cerrar
to close
cerrar
to close
cierro
I close
cerré
I close
cierras
you close (familiar)
cerraste
you close (familiar)
cierra
you close (formal), he closes, she closes
cerró
you closed (formal), he closed, she closed
cerramos
we close
cerramos
we closed
cerráis
you close (familiar plural)
cerrasteis
you closed (familiar plural)
cierran
you close (formal plural), they close
cerraron
you closed (formal plural), they closed


entender
to understand
entender
to understand
entiendo
I understand
entendí
I understood
entiendes
you understand (familiar)
entendiste
you understood (familiar)
entiende
you understand (formal), he understands, she understands
entendió
you understood (formal), he understood, she understood
entendemos
we understand
entendimos
we understood
entendeis
you understand (familiar plural)
entendisteis
you understood (familiar plural)
entienden
you understand (formal plural), they understand
entendieron
you understood (formal plural), they understand

Present tense stem changing -ir verbs in the preterite

-ir verbs, such as dormir and preferir, whose stems change in the present tense do change in the preterite tense – but in a slightly different way. The "o" in the verb stem of dormir changes to a "u" in the third person, singular and plural, and the "e" in the verb stem of preferir changes to an "i" in the third person, singular and plural. Read and listen to the following examples, then repeat each out loud.

dormir
to sleep
dormir
to sleep
duermo
I sleep
dormí
I slept
duermes
you sleep (familiar)
dormiste
you slept (familiar)
duerme
you sleep (formal), he sleeps, she sleeps
durmió
you slept (formal), he slept, she slept
dormimos
we sleep
dormimos
we slept
dormís
you sleep (familiar plural)
dormisteis
you slept (familiar plural)
duermen
you sleep (formal plural), they sleep
durmieron
you slept (formal plural), they slept


preferir
to prefer
preferir
to prefer
prefiero
I prefer
preferí
I preferred
prefieres
you prefer (familiar)
preferiste
you preferred (familiar)
prefiere
you prefer (formal), he prefers, she prefers
prefirió
you preferred (formal), he preferred, she preferred
preferimos
we prefer
preferimos
we preferred
preferís
you prefer (familiar plural)
preferisteis
you preferred (familiar plural)
prefieren
you prefer (formal plural), they prefer
prefirieron
you preferred (formal plural), they preferred