Il progetto coinvolge tre persone.

Because the subject is il progetto, which is singular.

• il progetto = the project
• coinvolge = it involves

In Italian, the verb must agree with the subject:

• il progetto coinvolge = the project involves
• i progetti coinvolgono = the projects involve

So coinvolge is the 3rd person singular form of coinvolgere in the present tense.

The dictionary form is coinvolgere, which means to involve.

In this sentence:

• coinvolgere = infinitive
• coinvolge = present tense, he/she/it involves

A quick present-tense pattern is:

• io coinvolgo = I involve
• tu coinvolgi = you involve
• lui/lei coinvolge = he/she involves
• noi coinvolgiamo = we involve
• voi coinvolgete = you all involve
• loro coinvolgono = they involve

Il is the definite article meaning the.

So:

• il progetto = the project

Italian usually uses articles more consistently than English. Here, il tells us we are talking about a specific project, not just any project.

Also, progetto is a masculine singular noun, so il is the correct article.

You mainly know from the article and the noun ending:

• il progetto → masculine singular
• nouns ending in -o are often masculine

So:

• progetto = masculine singular
• plural: progetti

Example:

• il progetto
• i progetti

As always, the article is a very useful clue.

After a number, Italian normally uses the noun without an article.

So:

• tre persone = three people

That is the normal pattern:

• due libri = two books
• quattro studenti = four students
• tre persone = three people

You would only add an article in more specific situations, such as talking about a known group in context.

Persone is plural.

The singular form is:

• persona = person

The plural is:

• persone = people / persons

So in this sentence:

• tre persone = three people

Also, persona is a feminine noun:

• una persona
• due persone

Even if the people are male, female, or mixed, the noun itself stays feminine because that is the grammatical gender of persona.

Because coinvolgere usually takes a direct object.

So Italian says:

• coinvolgere qualcuno = to involve someone

That means no a, con, or other preposition is needed here.

So:

• Il progetto coinvolge tre persone.
• literally: The project involves three people.

This works just like English involve someone.

This sentence uses the most neutral and common word order in Italian:

• Subject + Verb + Object
• Il progetto
  • coinvolge
    • tre persone

This is the standard order and the best one for learners to use.

Italian word order can change for emphasis, but this version is the most natural in ordinary speech and writing.

A rough pronunciation guide:

• il progetto ≈ eel pro-JET-to
• coinvolge ≈ koin-VOL-jeh
• tre persone ≈ treh per-SO-neh

A few details:

• In progetto, the gg sound is like the j in jam
• In coinvolge, the coi sounds roughly like koy
• The stress is:
  • proGEtto
  • coinVOLge
  • perSOne

Not always. Coinvolgere can have a few related meanings depending on context, such as:

• to involve
• to engage
• to include
• sometimes to affect or to draw in

In this sentence, to involve is the most natural meaning:

• Il progetto coinvolge tre persone. = The project involves three people.

But in other contexts, it might suggest emotional or active participation, not just simple inclusion.

Not with the same meaning.

• coinvolge tre persone = the project involves three people
• interessa tre persone = the project interests three people / concerns three people

So interessare changes the meaning. If you want the idea of participation or direct involvement, coinvolgere is the better verb.

Here is the breakdown:

• Il → definite article, masculine singular
• progetto → noun, masculine singular
• coinvolge → verb, present indicative, 3rd person singular of coinvolgere
• tre → cardinal number
• persone → noun, plural of persona

So the whole structure is:

• article + noun + verb + number + noun