Los portes del establecimiento son caros.

In Spain, portes usually means shipping charges, delivery charges, or postage costs.

It is a common commercial word, especially in:

• online shopping
• invoices
• store policies
• transport and delivery contexts

So in this sentence, los portes is not talking about doors or gates. It means the money charged for sending or delivering something.

It is often used in the plural because it refers to shipping costs/charges as a category of expense.

This is similar to how English often uses plural-style expressions like:

• shipping costs
• delivery charges

Spanish can use the singular porte, but in this kind of commercial context, los portes is very common.

So:

• el porte = the shipping charge / carriage
• los portes = the shipping charges

In practice, the plural is very normal in Spain when talking about what a business charges for delivery.

Because de + el contracts to del in Spanish.

So:

• de el establecimiento → del establecimiento

This is a standard grammar rule.

Examples:

• el libro del profesor
• la puerta del coche
• los horarios del museo

The only common exception is when el is part of a proper name, such as:

• de El Escorial

But here establecimiento is just a normal noun, so del is required.

Yes, here establecimiento means something like:

• business
• store
• shop
• commercial establishment

It is a bit more formal or general than tienda.

So:

• tienda = shop/store, everyday word
• establecimiento = establishment/business, more formal or administrative

A more everyday version of the sentence might be:

• Los portes de la tienda son caros.

That sounds slightly more conversational.

Because the subject is los portes, which is plural.

Spanish verbs and adjectives must agree with the noun they describe.

Here:

• los portes = masculine plural
• therefore son = plural form of ser
• and caros = masculine plural adjective

So the agreement is:

• los portes → son caros

Compare:

• El porte es caro.
• Los portes son caros.

Because it agrees with portes.

Porte is a masculine noun:

• el porte
• los portes

So the adjective must match:

• singular masculine: caro
• plural masculine: caros

Examples:

• El porte es caro.
• Los portes son caros.

If the noun were feminine plural, you would use caras:

• Las tarifas son caras.

It is understandable and natural, especially in a commercial, formal, or business context.

However, in everyday speech, many people might more naturally say:

• Los gastos de envío del establecimiento son caros.
• Los gastos de envío de la tienda son caros.
• El envío de esta tienda es caro.

So:

• los portes = perfectly valid, somewhat commercial or business-like
• los gastos de envío = often clearer and very common
• el envío = simpler, but slightly less precise if you want to emphasize the cost

They are very close in meaning, but there is a small nuance.

• portes is a more traditional/commercial term for carriage/shipping charges
• gastos de envío is more explicit and very common in modern retail and online shopping

In many situations, they can be used almost interchangeably.

For example:

• Los portes son caros.
• Los gastos de envío son caros.

Both mean that delivery/shipping costs are expensive.

If you want the most transparent phrase for a learner, gastos de envío is often easier to understand.

Because caros here describes an inherent or general characteristic of the shipping charges: they are expensive.

In Spanish, ser is typically used for:

• classification
• defining characteristics
• general descriptions

So:

• Los portes son caros. = The shipping charges are expensive.

Using estar would sound unusual here, because cost is not usually treated as a temporary state in this context.

No. Grammatically, caros describes los portes, not el establecimiento.

So the sentence means the shipping/delivery charges are expensive.

If you wanted to say the shop/business itself is expensive, you would say something like:

• El establecimiento es caro.
• Esta tienda es cara.

So the adjective agrees with and refers to the noun it matches:

• los portes ... caros
• el establecimiento ... caro

Yes, absolutely.

A very natural alternative is:

• Los portes de la tienda son caros.

This sounds more everyday and conversational.

Use:

• tienda for a normal shop/store
• establecimiento for a more formal or general business/premises/establishment

Both are correct; the choice depends on tone.