Ha giurato di non parlare.

Ha giurato is in the passato prossimo, a very common Italian past tense.

It is formed with:

• ha = present tense of avere (he/she has)
• giurato = past participle of giurare (sworn)

So literally it is something like has sworn, but in natural English it is usually translated as swore or has sworn, depending on context.

Because giurare normally takes avere as its auxiliary in compound tenses.

So:

• ha giurato = he/she swore
• not è giurato

In Italian, some verbs use essere and others use avere in the passato prossimo. Giurare is one of the verbs that uses avere.

Yes, the subject is not stated explicitly, which is very normal in Italian.

Ha giurato can mean:

• he swore
• she swore
• sometimes you swore in the formal Lei form, depending on context

Italian often leaves out subject pronouns when the verb form already makes it clear enough.

If you wanted to make it explicit, you could say:

• Lui ha giurato di non parlare.
• Lei ha giurato di non parlare.

Because after giurare, Italian commonly uses di + infinitive to mean to swear to do something.

So:

• giurare di dire la verità = to swear to tell the truth
• giurare di non parlare = to swear not to speak

This is a very common pattern in Italian:

• promettere di... = to promise to...
• decidere di... = to decide to...
• giurare di... = to swear to...

So di is the normal connector here.

Because in Italian, non normally comes before the verb it negates.

With an infinitive, that means:

• non parlare = not to speak
• non mangiare = not to eat
• non partire = not to leave

So di non parlare is the normal way to say to not speak / not to speak.

Yes. Parlare is the infinitive form, meaning to speak or to talk.

In this sentence:

• ha giurato = main verb
• di non parlare = infinitive phrase explaining what was sworn

So the structure is:

ha giurato + di + non parlare
swore + to + not speak

Normally, no. Standard Italian needs di here.

So the correct form is:

• Ha giurato di non parlare.

Without di, it sounds incomplete or ungrammatical in standard Italian.

No. It means He/She swore not to speak.

That is different from:

• Non ha giurato di parlare. = He/She didn’t swear to speak.

The position of non changes the meaning:

• ha giurato di non parlare
  = the speaking is negated
  = swore not to speak

• non ha giurato di parlare
  = the swearing is negated
  = did not swear to speak

This is an important difference.

Yes. Depending on context, giurare can be translated as:

• to swear
• to vow
• sometimes to take an oath

So Ha giurato di non parlare could be understood as:

• He swore not to speak
• He vowed not to speak

The exact English choice depends on tone and context.

Yes, it is perfectly natural Italian.

It sounds a bit serious because giurare is a strong verb. It suggests a firm promise, oath, or solemn declaration.

For example:

• Ha promesso di non parlare = He promised not to speak
  This is a bit less dramatic.
• Ha giurato di non parlare = He swore not to speak
  Stronger and more solemn.

So the sentence is natural, but it carries a serious tone.

Not here.

With avere, the past participle usually stays the same:

• Lui ha giurato
• Lei ha giurato

So giurato does not change to match a male or female subject in this sentence.

That is different from many verbs with essere, where the participle does agree:

• è andato / è andata

But here, with avere, you simply use ha giurato.