El actor con el papel secundario hace de apuntador.

Here hacer de means to act as, to serve as, or to play the part of.

So:

• hace de apuntador = acts as the prompter
• hacer by itself usually means to do or to make
• but hacer de + noun is a set expression meaning to perform the role/job of someone

Examples:

• Hace de médico en la obra. = He plays a doctor in the play.
• Hoy hago de conductor. = Today I’m acting as the driver.

Because hacer de often focuses on the role or function someone is performing, not necessarily their permanent identity.

• Es apuntador = He is a prompter.
  This sounds like that is his identity or profession.
• Hace de apuntador = He is acting as the prompter / taking the role of prompter.
  This emphasizes what he is doing in this situation.

In a theatre context, hacer de is very natural because people temporarily perform roles.

Literally, it means with the secondary role or with the supporting role.

In this sentence, it describes which actor we are talking about:

• El actor con el papel secundario = the actor with the supporting role / the actor who has the supporting role

So con here means something like having or associated with.

A more expanded version would be:

• El actor que tiene el papel secundario...

Yes, papel often means paper, but it also means role, part, or character role in theatre, film, and television.

So:

• papel principal = leading role
• papel secundario = supporting role
• hacer un papel = to play a role

This is a very common use of papel in Spanish.

In a theatre context, apuntador is the prompter: the person who helps actors by quietly giving them their lines if they forget them.

It comes from the verb apuntar, which can mean to prompt, to note down, or to point depending on context.

So here apuntador is not just any kind of pointer; it is specifically a theatre word.

Spanish uses definite articles like el, la, los, and las more often than English does.

Here:

• El actor = the actor
• el papel secundario = the supporting role

Even where English might sometimes omit the, Spanish often keeps it.

Also, el papel secundario suggests a specific role already understood from the context, not just any supporting role.

Yes, papel secundario is a normal and clear way to say supporting role.

Other possibilities exist depending on context, such as:

• papel de reparto
• papel secundario
• rol secundario (less traditional, but understood)

For many learners, papel secundario is the most straightforward and useful expression.

Because secundario agrees with papel, and papel is a masculine singular noun.

So:

• el papel secundario
• not el papel secundaria

Adjectives in Spanish must agree in gender and number with the noun they describe.

More examples:

• la actriz secundaria = the supporting actress
• los papeles secundarios = the supporting roles

It is grammatical, and the parts are understandable, but it feels a little unusual because of the situation it describes: an actor with a supporting role is acting as the prompter.

That may be perfectly fine in a specific story or theatre context, but out of context it sounds a bit unexpected.

The structure itself is natural:

• El actor con el papel secundario...
• hace de apuntador.

If you wanted a slightly more explicit version, you could say:

• El actor que tiene el papel secundario hace de apuntador.

Yes. If the prompter is female, you would normally use apuntadora.

For example:

• La actriz con el papel secundario hace de apuntadora.

Spanish nouns for people often change ending to match gender:

• actor / actriz
• apuntador / apuntadora

Hace is the present tense of hacer, third person singular:

• yo hago
• tú haces
• él/ella hace

So hace de apuntador means:

• he acts as the prompter
• he is acting as the prompter
• depending on context, sometimes even he plays the prompter

Spanish present tense can cover both a general present and what English sometimes expresses with is doing.