Conjugate stem changers in the preterite tense
Essential grammar #70
Stem changing infinitives
Stem changing infinitives are named for what they do– change in the stem.
You are going to make some alteration of the stem before adding the verb endings.
You will use the preterite endings you already know.
The hardest part of stem changers is knowing which ones change and which ones don’t.
Two Rules for identifying Preterite Stem-Changers:
1. The infinitive must be a stem-changer in the present tense.
2. The infinitive must end in –ir.
Stem changers
There are 2 different ways a stem changing infinitive can change (2 categories).
-The first is ou.
-This includes present tense oue.
dormir = to sleep
This is a stem changer in the preterite.First separate the stem from the infinitive ending.Dorm- is the stem.Make the stem change ouNew stem durm-Put into box– In the present tense, it looks like a boot. In the preterite tense, it looks like a sandal.Only the 3rd and 6th box make stem changes.
dormir = to sleep
dormí
dormí
dormiste
dormí
dormiste
durmió
dormí dormimos
dormiste
durmió
dormí dormimos
dormiste dormisteis
durmió
dormí dormimos
dormiste dormisteis
durmió durmieron
Stem changers
The second category is ei.
(This includes present tense changes eie and ei).
preferir = to prefer is a stem changer.
It is the same steps as dormir.
*When there is more than one vowel that could possible make the change, choose the vowel closest to the verb ending.
Preferir = to prefer
First separate the stem from the infinitive ending.
prefer- is the stem.
Make the stem change ei
New stem prefir-
Put into box– remember it will look like a sandal in the preterite. It will only change in the 3rd and 6th boxes.
preferir = to prefer
preferí
preferí
preferiste
preferí
preferiste
prefirió
preferí preferimos
preferiste
prefirió
preferí preferimos
preferiste preferisteis
prefirió
preferí preferimos
preferiste preferisteis
prefirió prefirieron
Stem changers
.
servir = to serve is a stem changer.
It is the same steps as preferir.
servir = to serve
First separate the stem from the infinitive ending.
serv- is the stem.
Make the stem change ei
New stem sirv-
Put into box– remember it will look like a sandal. In the preterite, only the 3rd and 6th boxes show change.
servir = to serve
serví
serví
serviste
serví
serviste
sirvió
serví servimos
serviste
sirvió
serví servimos
serviste servisteis
sirvió
serví servimos
serviste servisteis
sirvió sirvieron
Ellos pedir
Ella repetir
Nosotros sentir
Usted entender
Tú dormir
Ella seguir
Ellos pidieron
Ella repitió
Nosotros sentimos
Usted entendió
Tú dormiste
Ella siguió