Final answer:
The nosotros form for -er/-ir regular verbs in the preterite tense is conjugated by dropping the infinitive ending and adding -imos, such as comer to comimos and vivir to vivimos without stem changes for -ir verbs.
Step-by-step explanation:
The nosotros form for -er/-ir regular verbs in the preterite tense in Spanish typically ends with -imos. For example, the verb comer (to eat) in the nosotros form in preterite is comimos, and the verb vivir (to live) is vivimos.
To conjugate any regular -er or -ir verb in the preterite tense for the nosotros form, you simply drop the infinitive ending (-er or -ir) and add -imos. It's important to note that verbs ending in -ir that are stem-changing in the present tense do not have a stem change in the preterite for the nosotros form. So, a verb like dormir changes to dormimos, with no stem change as it would in the present tense.