Quiero cambiar de operador.

In Spanish, the subject pronoun yo is often omitted because the verb ending already shows who is doing the action.

• quiero = I want
• The -o ending tells you it is yo

So:

• Quiero cambiar de operador. = I want to change provider/operator.

You can say Yo quiero cambiar de operador, but it usually adds emphasis, contrast, or emotion:

• Yo quiero cambiar de operador, pero mi hermano no.
  I want to change provider, but my brother doesn’t.

Quiero is the first person singular (I) form of the verb querer.

Present tense of querer:

• yo quiero = I want
• tú quieres = you want
• él / ella / usted quiere = he/she/you want
• nosotros queremos = we want
• vosotros queréis = you all want
• ellos / ellas / ustedes quieren = they/you all want

A useful thing to notice: querer is a stem-changing verb:

• e → ie in most forms
• so querer becomes quiero, quieres, quiere, etc.
• but nosotros queremos and vosotros queréis do not change the stem

Because after querer, Spanish normally uses the infinitive.

Pattern:

• querer + infinitive
• Quiero comer. = I want to eat.
• Quiero salir. = I want to leave.
• Quiero cambiar de operador. = I want to change provider.

So cambiar stays in its dictionary form because it depends on quiero.

In this sentence, cambiar de means to switch/change from one thing to another of the same type.

So:

• cambiar de operador = to change provider / switch providers
• literally, something like change of provider

This is a very common structure in Spanish:

• cambiar de trabajo = change jobs
• cambiar de coche = change cars
• cambiar de ropa = change clothes
• cambiar de opinión = change one’s mind

Here, de is part of the usual expression.

This is a very useful distinction.

cambiar de + noun

This focuses on what you are leaving or replacing.

• Quiero cambiar de operador.
  I want to switch providers.

cambiar a + noun

This focuses on what you are moving to.

• Quiero cambiar a otro operador.
  I want to switch to another provider.

You can even use both ideas together:

• Quiero cambiar de operador a partir del mes que viene.
• Quiero cambiar a otra compañía.

In everyday use, cambiar de operador is very natural when the important idea is simply switching providers.

Because in Spanish, after cambiar de, the noun often appears without an article when speaking generally.

• cambiar de operador = change provider(s), switch providers
• cambiar de trabajo = change jobs
• cambiar de casa = move house / change homes

This sounds more general and idiomatic.

If you add an article, it usually becomes more specific:

• cambiar de un operador a otro = switch from one provider to another
• cambiar del operador actual = change away from the current provider

So in the original sentence, no article is the most natural general option.

Here operador most likely means a phone/mobile/internet provider or carrier, especially in Spain.

Depending on context, operador can mean different things:

• a machine operator
• a telephone operator
• a telecom provider/carrier

In this sentence, the most likely meaning is a telecom company.

In Spain, people also commonly say:

• operador móvil = mobile carrier
• compañía telefónica = telephone company
• proveedor = provider (more general, and often less colloquial in this context)

So cambiar de operador is a very natural way to say switch providers/carriers.

Yes. Quisiera cambiar de operador is more polite, softer, or less direct than Quiero cambiar de operador.

Compare:

• Quiero cambiar de operador. = I want to switch providers.
• Quisiera cambiar de operador. = I’d like to switch providers.

Both are correct. In customer service situations, quisiera often sounds more polite.

You could also hear:

• Me gustaría cambiar de operador. = I would like to switch providers.

In standard Spanish, the most natural version here is:

• Quiero cambiar de operador.

Using me with cambiar is possible in some contexts and varieties, but in this sentence it is usually unnecessary and may sound less standard depending on the region.

For a learner, the safest and most neutral option is:

• Quiero cambiar de operador.

If you want to sound natural in Spain, this is a very good choice.

You can add more information after it.

For example:

• Quiero cambiar de operador.
  I want to switch providers.

• Quiero cambiar a otro operador.
  I want to switch to another provider.

• Quiero cambiar de operador y pasarme a Vodafone.
  I want to switch providers and move to Vodafone.

• Quiero cambiar de operador porque pago demasiado.
  I want to switch providers because I pay too much.

In Spain, pasarse a is also very common for moving to another company:

• Quiero pasarme a otro operador.
  I want to switch to another provider.

In standard Spain Spanish, it is approximately:

KYEH-ro kam-BYAR de o-pe-ra-DOR

A few pronunciation notes:

• quiero: the ie sounds like ye in many explanations: KYE-ro
• cambiar: the c before a sounds like a normal k
• de operador: these words flow together smoothly in natural speech
• operador: stress is on the last syllable: -dor

A rough English-style approximation is:

KYEH-ro kahm-BYAR deh oh-peh-rah-DOR

Yes, quiero is in the present tense, but like English I want, it does not necessarily mean the action is happening right now at this exact second.

• Quiero cambiar de operador. can mean:
  • I want to switch providers now
  • I’m thinking about switching providers
  • I intend to switch providers

So the present tense here expresses a current desire or intention, not necessarily an action already in progress.