Vogliono fidanzarsi presto.

Vogliono is the third-person plural form of volere, which means to want.

So:

• voglio = I want
• vuoi = you want
• vuole = he/she wants
• vogliamo = we want
• volete = you all want
• vogliono = they want

In this sentence, vogliono means they want.

Italian often leaves out subject pronouns when they are not needed, because the verb ending already shows who the subject is.

Here, vogliono already tells you the subject is they, so loro is usually omitted.

You could say:

• Loro vogliono fidanzarsi presto.

But in normal Italian, that is usually unnecessary unless you want emphasis or contrast.

After volere (to want), Italian normally uses a direct infinitive, just like English:

• Vogliono fidanzarsi.
• They want to get engaged.

There is no preposition between volere and the infinitive.

Compare:

• voglio mangiare = I want to eat
• vuole partire = he/she wants to leave
• vogliono fidanzarsi = they want to get engaged

The -si shows that fidanzarsi is a reflexive verb.

The basic verb is related to fidanzare, but fidanzarsi means something like:

• to get engaged
• to become engaged to each other
• in some contexts, to start going out together

In this sentence, -si does not mean that each person is doing something separately to themselves. It is more of a reciprocal idea: the two people are becoming engaged to each other.

Not always. This is a word with some context-dependent nuance.

Depending on the situation, fidanzarsi can mean:

• to get engaged
• to become a couple
• to start dating seriously

Also, fidanzato / fidanzata can mean either:

• boyfriend / girlfriend or
• fiancé / fiancée

So the exact meaning depends on context. If the meaning shown to the learner is to get engaged, that is a perfectly normal reading here, especially with presto.

Here presto means soon.

So:

• Vogliono fidanzarsi presto. = They want to get engaged soon.

Presto can also mean early in other contexts, but with a verb like fidanzarsi, soon is the natural meaning.

Compare:

• Si sono svegliati presto. = They woke up early.
• Vogliono sposarsi presto. = They want to get married soon.

Yes. Italian adverbs are often somewhat flexible in position.

You may see:

• Vogliono fidanzarsi presto.
• Vogliono presto fidanzarsi.

The first one is more natural and common in everyday speech.

Placing presto after the infinitive is very normal because it clearly modifies the action fidanzarsi.

A learner often notices the tricky gli sound in vogliono.

A rough pronunciation is:

• VO-lyo-no

The gli here is not like English glee. It is a special Italian sound, similar to the lli in some pronunciations of Spanish calle, or like a softened ly sound.

So:

• vogliono ≈ VO-lyo-no

This is one of the most common pronunciation challenges for English speakers.

A rough guide is:

• fee-dan-TSAR-see

A few notes:

• fi = fee
• zan here sounds like tsan
• -arsi = AR-see

The stress falls on -zar-:

• fi-dan-ZAR-si

Yes, only the form of volere would change. The infinitive fidanzarsi stays the same.

Examples:

• Vuole fidanzarsi presto. = He/She wants to get engaged soon.
• Vogliamo fidanzarci presto. = We want to get engaged soon.

Notice something important in the we version:

• fidanzarsi becomes fidanzarci

That is because the reflexive ending changes to match the subject:

• -mi = myself
• -ti = yourself
• -si = himself/herself/themselves
• -ci = ourselves
• -vi = yourselves

That would usually mean something different or sound awkward depending on context.

• Vogliono fidanzarsi presto = They want to get engaged soon.

This is the standard way to say that they want to do it.

If you say si vogliono fidanzare, the structure becomes less straightforward and may suggest a different construction involving pronouns. For a learner, the safest and most natural version is definitely:

• Vogliono fidanzarsi presto.

Yes. Vogliono is in the present tense.

But the sentence is about a present desire concerning a future action:

• right now, they want
• the engagement is expected soon

This is very normal in both Italian and English.

So the timeline is:

• present feeling/wish: they want
• future action: to get engaged soon