In Italian, a direct object pronoun is placed immediately before a conjugated verb:

Se vediamo i ragazzi, li invitiamo. (If we see the boys, we’ll invite them.)

Compra la frutta e la mangia. (He buys the fruit and eats it.)

The only exception to that is when a sentence contains an infinitive. In this case, the object pronoun is attached to the end of it (note that the final -e of the infinitive is dropped):

è importante mangiarla ogni giorno. (It is important to eat it every day.)

è una buon’idea invitarli. (It’s a good idea to invite them.)

In a negative sentence, the word non must come before the object pronoun: