In the Spanish preterite tense, there are several common -ir verbs where the stem changes to form the correct verb conjugation.
Stem-changing -ir verbs fall into three categories in the preterite: e -> i, o -> u, and e -> ie.
This means that in certain conjugations, the ‘e’ changes to ‘i‘, the ‘o‘ to ‘u‘, or the ‘e‘ to ‘ie‘. However, it’s crucial to note that these changes occur only in the third person singular (él, ella, usted) and third person plural (ellos, ellas, ustedes) forms.
- E -> I Stem-changing Verbs: In this category, the ‘e‘ in the stem changes to ‘i‘. For instance, the verb ‘servir‘ (to serve) becomes ‘sirvió‘ in the third person singular and ‘sirvieron’ in the third person plural.
- O -> U Stem-changing Verbs: Here, the ‘o‘ in the stem changes to ‘u‘. For example, the verb ‘dormir‘ (to sleep) becomes ‘durmió‘ in the third person singular and ‘durmieron‘ in the third person plural.
- E -> IE Stem-changing Verbs: This is a smaller group, with ‘e’ changing to ‘i’. ‘Preferir‘ (to prefer) is an example of this, becoming ‘prefirió‘ in the third person singular and ‘prefirieron‘ in the third person plural.
Remember that other forms (yo, tú, nosotros/nosotras) of these verbs do not experience stem changes in the preterite tense.
Additionally, most -ir verbs do not have stem changes. Therefore, the key to mastering stem-changing verbs in the Spanish preterite tense lies in familiarizing yourself with common verbs that follow these rules and practicing their correct conjugation. Regular use and practice will aid in intuitively recognizing and applying these rules in everyday conversation.