<p>When the auxiliary verb of a compound form is <span style="font-style: italic;">avere</span>, <strong>the past participle does not agree in number and gender</strong> with its subject. There are two exceptions to this rule:</p>
<ul>
<li><p>When a <strong>third-person direct object pronoun precedes</strong> the verb (with first-person and second-person pronouns, the agreement is optional). In this case, the <span class="green_emphasis">past participle</span> has to agree with the <span class="brown_emphasis">pronoun</span> in gender and number:</p>
<div class="conjugation_explanation_example_sentence">Non <span class="brown_emphasis">le</span> ho <span class="green_emphasis">viste</span> recentemente. (<span style="font-style: italic;">I haven't seen them recently.</span>)</div>
</li>
<li><p>When the <strong>pronoun NE precedes</strong> the verb, the <span class="green_emphasis">past participle</span> has to agree with the <span class="brown_emphasis">word</span> that the pronoun replaces:</p>
<div class="conjugation_explanation_example_sentence"><strong>Ne</strong> hanno <span class="green_emphasis">trovata</span> <span class="brown_emphasis">una</span>. (<span style="font-style: italic;">They found one.</span>)</div>
<div class="conjugation_explanation_example_sentence">Ho comprato delle <span class="brown_emphasis">fragole</span> e <strong>ne</strong> ho <span class="green_emphasis">mangiate</span> tante. (<span style="font-style: italic;">I bought some strawberries and ate a lot of them.</span>)</div>
Italian conjugation explanation