translation question

Jim's right. the grammatical structure of the sentence is this:

Je --> subject
ai vu --> conjugated verb (ai) and participle (vu) to form the passé composé
Sharon Stone  --> direct object
descendre de la limousine --> infinitive clause  further specifying the direct object

A verb is only conjugated in accordance with the subject, never the direct object. That's why descendre is the infinitive.

Bonjour Alexis,

The subject of the sentence is I (je) the verb (voir) is conjugated in the passé composé and the object is Sharon Stone.

There is no requirement to conjugate the verb descendre (get out of (de) a limo) and that is why it is in the infinitive.

I hope this helps.

Bonne continuation.

Jim