Marco è ebreo.

Because è is the verb essere (to be) in the he/she/it is form.

• è = is
• e = and

So the accent is important because it distinguishes two different words:

• Marco è ebreo = Marco is Jewish.
• Marco e Paolo = Marco and Paolo.

In Italian, after essere, words for religion, nationality, political identity, and many general categories are often used without an article.

So:

• Marco è ebreo = Marco is Jewish / Marco is a Jew

This is very natural Italian.

You can also hear:

• Marco è un ebreo

but that sounds a little more like Marco is a Jew, with more emphasis on the noun category. In many everyday contexts, Marco è ebreo is the more neutral and common way.

It can be understood either way, depending on how you analyze it.

• As an adjective, it means Jewish.
• As a noun, it means a Jew.

In this sentence, Italian allows this kind of overlap, and the meaning is usually clear from context. A learner can safely understand Marco è ebreo as Marco is Jewish.

In Italian, words for religions, nationalities, and languages are usually not capitalized unless they begin the sentence.

So Italian writes:

• ebreo
• italiano
• inglese
• cristiano

This is different from English, where Jewish is capitalized.

A simple guide is:

• Marco = MAR-ko
• è = eh
• ebreo = eh-BREH-o

So the whole sentence sounds roughly like:

MAR-ko eh eh-BREH-o

A useful note: ebreo has three syllables:

• e-bre-o

It is the third person singular present tense of essere.

The present tense of essere is:

• io sono = I am
• tu sei = you are
• lui/lei è = he/she is
• noi siamo = we are
• voi siete = you all are
• loro sono = they are

Since Marco is he, Italian uses è.

Normally, no, not for a person.

• ebreo is the usual word for a Jewish person.
• ebraico usually means Hebrew or Jewish in a more cultural, historical, or linguistic sense.

For example:

• la lingua ebraica = the Hebrew language
• la tradizione ebraica = Jewish tradition

But for a person, Marco è ebreo is the normal choice.

It can refer to both, depending on context, just like English Jewish or a Jew can.

So Marco è ebreo could describe:

• Marco’s religion
• Marco’s ethnic/cultural identity
• both

The sentence itself does not force only one interpretation; context decides.

The word must agree with the person’s gender.

• masculine singular: ebreo
• feminine singular: ebrea

So:

• Marco è ebreo.
• Sara è ebrea.

Agreement is very important in Italian adjectives and many identity words.

You change both the subject and the predicate as needed.

• masculine plural: ebrei
• feminine plural: ebree
• mixed group or unspecified masculine plural: ebrei

Examples:

• Marco e Davide sono ebrei. = Marco and Davide are Jewish.
• Sara e Lea sono ebree. = Sara and Lea are Jewish.

Also notice:

• è becomes sono in the plural.

Yes, but Marco è ebreo is the normal, neutral order.

Italian can sometimes change word order for emphasis, for example:

• Ebreo è Marco — possible, but unusual and strongly marked

For everyday speech and writing, stick with:

• Marco è ebreo

Because essere is used for identity, category, and essential description.

Here, ebreo describes who Marco is, so Italian uses essere:

• Marco è ebreo.

Stare is used more for condition, location in some expressions, or temporary states, not for this kind of identity statement.

Yes, you can, but the nuance is slightly different.

• Marco è ebreo = neutral, very natural, often best translated as Marco is Jewish
• Marco è un ebreo = more explicitly Marco is a Jew, with a bit more focus on classifying him as a member of that group

Both are grammatical, but if you are unsure, Marco è ebreo is a very safe and natural choice.