Whats the difference between stem changing in the present tense and the preterite?
-ar and -er verbs that change their stem in the present tense do not change in the preterite. They are conjugated just like other regular preterite verbs, using the regular endings.
cerrar
cerré
cerraste
cerró
cerramos
cerrasteis
cerraron
entender
entendí
entendiste
entendió
entendimos
entendisteis
entendieron
-ir verbs that change their stem in the present tense do change in the preterite, but in a different way. They change e:i and o:u in the third person, singular and plural.
preferir
preferí
preferiste
prefirió
preferimos
preferisteis
prefirieron
dormir
dormí
dormiste
durmió
dormimos
dormisteis
durmieron
To understand the difference between stem changing verbs in the present tense and the preterite tense, we need to first understand what stem changing verbs are.
Stem changing verbs, also called e > ie, o > ue, and e > i verbs, are a type of verbs in Spanish that undergo a change in their stem vowel when conjugated. The change occurs in the present tense and the preterite tense, but the patterns are different.
In the present tense, stem changing verbs experience a vowel change in all forms except for nosotros and vosotros. Let's take the verb "pensar" (to think) as an example:
- In the present tense, the stem "pens-" changes to "piens-" in the indicative forms (except for nosotros and vosotros). For example:
- Yo pienso (I think)
- Tú piensas (You think)
- Él/Ella/Usted piensa (He/She/You think)
On the other hand, in the preterite tense, stem changing verbs have a different pattern. Let's use the verb "entender" (to understand) as an example:
- In the preterite tense, the stem "entend-" changes to "entiend-" in the third person singular (él/ella/usted) and third person plural (ellos/ellas/ustedes) forms. For example:
- Él/Ella/Usted entendió (He/She/You understood)
- Ellos/Ellas/Ustedes entendieron (They/You all understood)
It's important to note that not all verbs follow the same pattern, but these examples should help you understand the general idea of stem changes in the present tense and preterite tense.
To identify stem changes in other verbs, you would need to identify the infinitive form of the verb, isolate the stem (the part before the -ar, -er, or -ir ending), and then check how it changes depending on the tense. There are some patterns and irregularities to watch out for, so it's recommended to refer to a reliable conjugation resource or a Spanish grammar guide for specific verb conjugations.