词干变化动词 E:I

 The main form of the verb is called the infinitive. The infinitive consists of two parts: the ending and the stem. The ending is the last two letters. There are only three different endings: -ar, -er, and -ir. The stem is everything else, except the ending.

hablar: ending = ar, stem = habl

comer: ending = er, stem = com

vivir: ending = ir, stem =viv

Some spanish verbs are called stem-changers because when they are conjugated, the stem changes in a predictable way. In one group of stem-changing verbs, the letter e in the stem changes to i in all but the nosotros and vosotros forms. This particular type of stem-changing verb is found only in -ir verbs.

pedir

yo pido

tú pides

él, ella, Ud. pide

nosotros/as pedimos

vosotros/as pedís

ellos, ellas, Uds. piden

For a more complete discussion of verbs that change e:i click here.

Here are some common e:i stem-changing verbs.

competir

to compete

concebir

to conceive

despedir

to fire

impedir

to impede

medir

to measure

pedir

to ask for

re?ir

to scold, quarrel

repetir

to repeat

servir

to serve

te?ir

to color, dye, stain

vestir

to dress