Fill in the blank with the correct conjugation of the verb in parentheses.

¿Cuándo __________ usted (necesitar) el libro?

When entering your answers for fill in the blank and essay questions, please be sure to use accent marks and/or correct punctuation to avoid your answer being marked incorrect.

You may copy and paste the accented character or punctuation mark from this list if needed:
á é í ó ú ñ Á É Í Ó Ú ¿ ¡