Preterite Spelling-Change Verbs
The following changes occur in the yo form only:
Verbs that end in -gar change g to gu
Verbs that end in -car change c to qu
Verbs that end in -zar change z to c
Examples:
jugué (jugar)
busqué (buscar)
almorcé (almorzar)
Here are some examples of common verbs in this category:
jugar
llegar
pagar
rogaraparcar
buscar
clasificar
tocaralmorzar
comenzar
empezar
organizar
For verbs that end in -aer, -eer, -´Çðù, and -oer, the él,/ella/usted form uses the ending ²âó (rather than ió) and the third person plural uses the ending yeron (rather than ieron). The remaining forms gain a written accent over the letter i.
Example: creer
creÃ
creÃste
cre²âó
creÃmos
creÃsteis
creyeron
Other verbs like creer include:
caer
leer
´Çðù
poseer
proveer
roer
Exceptions to this rule include:
traer
atraer
distraer
Verbs that end in -uir change in the same way, but the written accent over the letter i only occurs in the yo form.
Example: huir
huÃ
huiste
hu²âó
huimos
huisteis
huyeron
Other verbs like huir include:
construir
contribuir
destruir
fluir
incluir
influir