Preterite - stem-changing verbs

The preterite is one of the two simple past tenses in Spanish. It is used when the speaker wants to focus on the beginning or ending of an action in the past.

If a verb is a stem changer in the present tense, it will not stem-change in the preterit unless it is an - ir verb. No - ar or - er verbs will stem-change in the preterit.

The verb mentir (to lie) is an ir verb that undergoes a stem change from (e) to (i). The congugation of mentir is shown in the table below. Other verbs that follow this pattern are: hervir (to boil), preferir (to prefer), sentir (to feel), convertir (to convert), and divertirse (to enjoy yourself).

mentir(example sentences) (full conjugation)

   
yo
   
mentí
   
(I told a lie)


   
tú
   
mentiste
   
(you told a lie)


   
Ud./él/ella
   
mintió
   
(he told a lie)


   
nosotros as
   
mentimos
   
(we told a lie)


   
vosotros as
   
mentisteis
   
(you guys told a lie)


   
Uds./ellos/ ellas
   
mintió
   
(you all/they told a lie)

The verb pedir (to request) is an ir verb that undergoes a stem change from (e) to (i). The congugation of pedir is shown in the table below. Other verbs that follow this pattern are: seguir (to follow), medir (to measure), repetir (to repeat), impedir (to prevent), and reñir (to argue).

pedir (example sentences) (full conjugation)

    
yo
    
pedí
    
(I requested)


    
tú
    
pediste
    
(you requested)


    
Ud./él/ella
    
pidió
    
(you/he/she requested)


    
nosotros as
    
pedimos
    
(we requested)


    
vosotros as
    
pedisteis
    
(you guys requested)


    
Uds./ellos/ ellas
    
pidieron
    
(they requested)

Note:
m = male f = female mix = mixed group
yo = I, tú = you (informal)
usted (Ud.) = you (formal)
él = he, ella = she
nosotros = we (m/mix), nosotras = we (f)
vosotros = you guys (informal, m/mix)
vosotras = you guys (informal, f)
ellos = they (m/mix), ellas = they (f)
ustedes (Uds.) = you all (formal)