Final answer:
The verb form that completes the sentence is 'hablábamos'.
Step-by-step explanation:
In this sentence, the verb that completes the sentence needs to agree in form and tense with the subject 'mi amiga y yo' (my friend and I). The correct verb form is hablábamos because it agrees with the subject in both number (plural) and tense (past).
Learn more about verb forms in Spanish