When describing an action you perform without doing something else, Italian uses the preposition senza (without) followed by an infinitive verb, provided the subject is the same for both actions.
Senza + Present Infinitive
Use senza with a present infinitive to describe skipping an action that would normally happen at the same time, or to describe how you do something (such as acting quietly or stealthily).
| One does not enter without knocking. | Non si entra senza bussare. |
| We went out without waking the grandfather. | Siamo usciti senza svegliare il nonno. |
If the verb takes an object or reflexive pronoun, drop the final -e of the infinitive and attach the pronoun directly to the end.
| She closed the door without slamming it. | Ha chiuso la porta senza sbatterla. |
| I got up without waking him up. | Mi sono alzato senza svegliarlo. |
Senza + Past Infinitive
If the action you didn't do is in the past relative to the main action (meaning "without having done" it), use senza followed by a past infinitive. You form this by combining the infinitive of the auxiliary verb (avere or essere) with the past participle of the main verb.
| He passed the exam without having studied. | Ha superato l'esame senza aver studiato. |
| He answered without having understood the question. | Ha risposto senza aver capito la domanda. |
Pronoun rules remain exactly the same: attach them directly to the end of the auxiliary verb's infinitive.
| He left without having said goodbye to me. | Se n'è andato senza avermi salutato. |