Hemos de pagar el anticipo antes del montaje.

Because hemos can be part of two different structures:

• hemos pagado = we have paid
  This is the present perfect: haber + past participle
• hemos de pagar = we have to pay / we must pay
  This is haber de + infinitive, which expresses obligation or sometimes a fairly formal sense of necessity.

So in this sentence, de pagar is what tells you it is not a perfect tense, but an obligation structure.

Almost, yes. Both usually mean we have to pay.

The difference is mostly one of style and register:

• tenemos que pagar = the most common, neutral everyday way
• hemos de pagar = correct, but often sounds a bit more formal, written, or administrative

In a business or contractual context, hemos de pagar el anticipo antes del montaje sounds quite natural.

It is a structure used to express obligation, duty, or sometimes what is expected to happen.

Pattern:

• haber
  • de
    • infinitive

Examples:

• He de salir = I have to leave
• Has de firmar aquí = You have to sign here
• Hemos de pagar = We have to pay

For this sentence:

• hemos = first person plural of haber
• de = part of the structure
• pagar = infinitive, to pay

So the whole phrase means we are required to pay.

Because the subject is we.

Here are the present-tense forms of haber in this structure:

• he de = I have to
• has de = you have to
• ha de = he/she has to
• hemos de = we have to
• habéis de = you all have to (Spain)
• han de = they have to

Since the sentence refers to we, Spanish uses hemos de.

Here anticipo means an advance payment, deposit, or upfront payment.

In practical business contexts, it often refers to money paid before the full service is completed.

Depending on context, English translations could be:

• deposit
• advance payment
• down payment

So pagar el anticipo means to pay the deposit / advance payment.

Because Spanish often uses the definite article where English may or may not use one.

el anticipo means:

• the deposit
• or more naturally in English, sometimes just the deposit/payment due in advance

It refers to a specific payment that both sides already know about, such as the deposit required for a job or service.

Using just anticipo without the article would usually not sound right in this sentence.

In this context, montaje most likely means installation or assembly.

In Spain, montaje is commonly used for:

• putting furniture together
• installing equipment
• setting something up physically

So antes del montaje means before the installation / before the assembly work.

Be aware that montaje can mean other things in other contexts, such as:

• editing in film
• a set-up or even a staged scheme

But here the business/service meaning is the natural one.

Because de + el contracts to del.

So:

• de el montaje becomes del montaje

This contraction is mandatory in normal Spanish.

The same happens with:

• a + el = al

Examples:

• antes del pago = before the payment
• vamos al taller = we go to the workshop

Antes de means before.

When it comes before a noun, the structure is:

• antes de + noun

Since el montaje is a noun phrase, you get:

• antes del montaje

Compare:

• antes del montaje = before the installation
• antes de montar = before assembling/installing

Both are possible, but they are built differently:

• antes de + noun
• antes de + infinitive

Yes. That is the most straightforward everyday equivalent.

Compare them:

• Hemos de pagar el anticipo antes del montaje
  Slightly more formal, administrative, or written
• Tenemos que pagar el anticipo antes del montaje
  Very common and natural in everyday speech

The meaning is basically the same.

Yes, but that is normal in Spanish.

Spanish usually omits subject pronouns when the verb already shows who the subject is.

• Hemos already tells you the subject is we
• So Nosotros hemos de pagar... is possible, but usually unnecessary

You would add nosotros only for emphasis, contrast, or clarity.

The order is very standard:

• Hemos de pagar = verb phrase
• el anticipo = direct object
• antes del montaje = time phrase

So it follows a common pattern: verb + object + time expression

It sounds natural and unmarked. Spanish could rearrange parts for emphasis, but this version is the most neutral.

It works in Spanish generally, but it does have a slightly Spain/business-register feel.

Reasons:

• hemos de + infinitive is especially common in formal or written Spanish
• montaje for installation/assembly is very common in Spain
• in some regions of Latin America, speakers might prefer alternatives like tenemos que or different vocabulary depending on the industry

So the sentence is perfectly understandable across the Spanish-speaking world, but it fits Spain very well.