Final answer:
The sentence's imperfect verb form is correct.
Step-by-step explanation:
The given sentence, Mi familia fuera la más grande, contains the imperfect form of the verb 'fuera', which means 'to be' or 'was' in English. In this sentence, 'fuera' is used correctly in the imperfect tense, which indicates an ongoing or repeated action in the past. The use of the imperfect tense in this sentence suggests that the speaker's family used to be the biggest (la más grande) in the past, but it may not be the case anymore.
Learn more about Spanish verb conjugation