Answer:
The right conjugation of the verb <em>"volver"</em> is:
- <u><em>Vuelto</em></u><em>.</em>
<em>- </em><em>Armando no había </em><u><em>vuelto</em></u><em> a la escuela antes de que su madre me llamó.</em>
Explanation:
The translation of the sentence is:
- Armando had not <u>returned</u> to school before his mother called me.
At the time of conjugating a verb, regularly the first thing that must be identified is the tense in which the sentence or text is found, in this case, since the verb <em>"haber"</em> is presented, in its form <em>"había,"</em> the tense is perfect compound, which is characterized by having its second verb with endings <em>"ado"</em> or <em>"ido,"</em> but in the case of the verb <em>"volver,"</em> the right conjugation form is not <em>"volvido,"</em> that form doesn't exist, in change, it is an irregular verb whose form in perfect tense is <u><em>"vuelto."</em></u>