Un prestador de servicios de confianza comprueba el certificado electrónico cualificado.

Un means a / an, while el means the.

Here, un prestador de servicios de confianza usually means a trust service provider in a general sense: any provider of that type.

• Un prestador... = a provider / any provider
• El prestador... = the provider / a specific provider already known from the context

In technical or legal Spanish, un is often used when describing what a member of a category does in general.

Prestador comes from the verb prestar and is a formal, technical noun meaning provider or supplier of a service.

In everyday Spanish, learners often know proveedor first, but prestador is very common in legal, administrative, and regulatory language, especially in expressions like:

• prestador de servicios
• prestador de servicios de confianza

So prestador sounds more official and specialized here.

Spanish often links nouns together with de where English uses stacked nouns.

So:

• prestador de servicios = provider of services
• servicios de confianza = trust services

Put together:

• prestador de servicios de confianza = provider of trust services

English can pile nouns together more easily, but Spanish usually needs de to connect them.

Because these nouns are being used to classify or define the type of provider and the type of services, not to refer to specific ones.

So:

• prestador de servicios = provider of services
• servicios de confianza = trust services

This is very common in Spanish. Compare:

• una taza de café
• un profesor de español
• una empresa de tecnología

If you added articles, the meaning would become more specific:

• prestador de los servicios = provider of the services
• servicios de la confianza would not work here

Comprueba is the third-person singular present indicative of comprobar.

So it means:

• he/she checks
• it checks
• checks / verifies

In this sentence, the subject is un prestador de servicios de confianza, which is singular, so the verb is singular too:

• Un prestador ... comprueba ...

Related forms:

• yo compruebo
• tú compruebas
• él/ella/usted comprueba

It can mean both, depending on context.

In everyday Spanish, comprobar often means to check.
In technical, administrative, or legal contexts, it often has the stronger sense of to verify.

So in this sentence, verifies is often the best English choice, even though checks is also possible.

El suggests a specific certificate is being referred to.

So the sentence is not talking about just any certificate in general, but about the certificate relevant in that context.

Compare:

• comprueba un certificado = checks a certificate
• comprueba el certificado = checks the certificate

In technical writing, Spanish often uses the definite article when the item is understood from the situation.

In Spanish, adjectives usually come after the noun, especially in technical or descriptive language.

So:

• certificado electrónico = electronic certificate
• certificado cualificado = qualified certificate

When both adjectives appear, they normally stay after the noun:

• certificado electrónico cualificado

This is much more natural in Spanish than putting the adjectives before the noun.

Cualificado agrees with certificado, which is:

• masculine
• singular

So the adjective is also masculine singular:

• certificado ... cualificado

If the noun changed, the adjective would change too:

• certificados ... cualificados
• firma cualificada
• firmas cualificadas

The same is true of electrónico:

• certificado electrónico
• certificados electrónicos

Yes. Both adjectives modify certificado.

So the structure is:

• el certificado = the certificate
• electrónico = electronic
• cualificado = qualified

Together: the qualified electronic certificate.

In legal/technical Spanish, this whole phrase is often treated as a set expression.

Grammatically, Spanish adjective order can sometimes vary, but in this technical phrase, certificado electrónico cualificado is the natural and expected wording.

In legal and EU-style terminology, the order is usually fixed because it reflects a recognized category. So even if another order might be understandable, it would sound odd or less standard.

Because el certificado is a thing, not a person.

Spanish uses the personal a mainly with direct objects that are people (and sometimes pets or personified beings).

Compare:

• comprueba el certificado = no a, because it is an object/thing
• ve al técnico = a is used, because técnico is a person

Yes, this is active voice:

• Un prestador ... comprueba el certificado ...

Spanish could also use a passive construction, but the active is more direct and much more common in normal technical writing.

Possible passive-style versions might be:

• El certificado electrónico cualificado es comprobado por un prestador de servicios de confianza.
• Se comprueba el certificado electrónico cualificado.

But the original active version sounds more natural.

In Spain, it is pronounced approximately:

• e-lek-TRÓ-ni-ko

The stress falls on tró because of the written accent: electrónico.

Also, in most of Spain, the c before e is pronounced like the th in thin:

• elec- sounds roughly like eleth-

So in Peninsular Spanish, the word sounds roughly like:

• eh-lek-THRÓ-nee-ko

Not really. Even though that is the literal breakdown, the actual meaning is the technical/legal concept trust services.

So de confianza here should not be interpreted in the everyday sense of trustworthy or trusted in a loose way. It is part of a set legal expression.

That is why translating word by word can be misleading here. The whole chunk servicios de confianza functions as one technical term.