Pagamos el anticipo antes del montaje.

Spanish often leaves out subject pronouns because the verb ending already shows who is doing the action.

• Pagamos = we pay or we paid
• The ending -amos tells you the subject is nosotros

So Nosotros pagamos el anticipo antes del montaje is correct, but nosotros is usually omitted unless you want emphasis or contrast.

It can mean either one, depending on context.

• Present tense: we pay
• Preterite: we paid

This happens because for -ar verbs, the nosotros form is the same in the present and the preterite:

• pagamos = we pay
• pagamos = we paid

Usually the surrounding context makes it clear. For example:

• Normalmente pagamos el anticipo antes del montaje = We normally pay the deposit before installation
• Ayer pagamos el anticipo antes del montaje = Yesterday we paid the deposit before installation

Anticipo usually means an advance payment, deposit, or sometimes down payment, depending on the situation.

In this sentence, it means money paid before the full service or job is completed. A very natural English equivalent is often deposit or advance payment.

So:

• pagar el anticipo = to pay the deposit / advance payment

Spanish uses articles much more often than English.

Here, el anticipo refers to a specific payment that both speaker and listener understand: the deposit / the advance payment.

In English, we might sometimes say just pay a deposit or pay the deposit, but in Spanish the article is very commonly used:

• Pagamos el anticipo = We pay/paid the deposit

If you said un anticipo, that would mean a deposit / an advance payment, usually introducing it as less specific.

Because de + el contracts to del in Spanish.

So:

• antes de el montaje → incorrect
• antes del montaje → correct

This contraction happens almost always with de + el:

• del = de + el

A similar contraction happens with a + el:

• al = a + el

Antes often needs de when it is followed by a noun, pronoun, or infinitive.

Here it is followed by the noun phrase el montaje, so you need de:

• antes del montaje = before the installation / assembly

Compare:

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

So the structure is:

• antes de + noun
• antes de + infinitive

Montaje can mean different things depending on context, but here it most likely means:

• installation
• assembly
• setup

In business, furniture, construction, or technical contexts in Spain, montaje often refers to the act of putting something in place or installing it.

So antes del montaje would usually mean before the installation or before assembly.

Because in Spanish, a noun like montaje usually needs an article unless it is being used in a more general or special structure.

Here, el montaje refers to a specific installation or assembly event, so the article sounds natural and standard:

• antes del montaje = before the installation

Antes de montaje would sound incomplete or unnatural in normal Spanish.

In Spanish, pagar usually takes a direct object without a preposition when you mean paying an amount, bill, fee, deposit, and so on.

So:

• pagar el anticipo = to pay the deposit
• pagar la cuenta = to pay the bill
• pagar una multa = to pay a fine

Spanish does not usually say pagar por el anticipo in this context.

Yes. That is perfectly correct.

Spanish word order is more flexible than English. Both versions are natural:

• Pagamos el anticipo antes del montaje
• Antes del montaje pagamos el anticipo

The second version puts more focus on the time expression before the installation.

A simple pronunciation guide is:

pah-GAH-mos el an-tee-SEE-po AN-tes del mon-TA-he

A few points for Spain:

• c before i in anticipo is pronounced like the th in thin in much of Spain
• j in words like montaje is a strong throaty sound
• The stress falls on:
  • pagamos → GA
  • anticipo → CI
  • antes → AN
  • montaje → TA

Yes. It sounds very natural in contexts where a company or customer pays part of the cost before work begins.

Typical situations include:

• furniture assembly
• kitchen installation
• construction work
• event setup
• custom orders

So it is a very useful real-life sentence for professional and practical Spanish.