La clonación de la tarjeta causa un cargo no reconocido.

Because clonación is a noun, not a verb. The sentence needs a subject, and here the subject is la clonación de la tarjeta.

• clonar = to clone
• la clonación = the cloning

So the structure is:

• La clonación de la tarjeta = the cloning of the card
• causa = causes
• un cargo no reconocido = an unrecognized charge

Also, nouns ending in -ción are usually feminine, which is why it is la clonación.

De often means of. Here it links clonación with tarjeta:

• la clonación de la tarjeta = the cloning of the card

This is a very common Spanish structure:

• la pérdida de la cartera = the loss of the wallet
• el robo del coche = the theft of the car

So de la tarjeta tells you what is being cloned.

Spanish uses articles more often than English does. In this sentence, la tarjeta refers to a specific card, or to the card involved in the situation.

Compare:

• la tarjeta = the card
• una tarjeta = a card

If you said la clonación de una tarjeta, that would sound more general: the cloning of a card. But de la tarjeta points more naturally to a particular card.

Because the subject is singular:

• La clonación de la tarjeta = singular

So the verb must also be singular:

• causa = it causes

Compare:

• La clonación de la tarjeta causa... = singular
• Las clonaciones de tarjetas causan... = plural

And causar is the infinitive, meaning to cause, so it would not work here as the main conjugated verb.

Here, cargo means a charge, especially a bank charge or card charge.

This is important because cargo is a false friend for English speakers. It does not mean shipping goods here.

In financial Spanish:

• un cargo = a charge/debit
• un abono = a credit/payment in

So un cargo no reconocido is a charge on your account or card statement that you do not recognize.

Because cargo and carga are different words.

• cargo = charge, debit, position/job title, responsibility
• carga = load, burden, cargo/freight

In banking, the correct word is cargo. So:

• un cargo en la cuenta = a charge on the account

Not una carga.

In Spanish, adjectives usually come after the noun, especially when they describe a factual quality.

So:

• un cargo no reconocido = an unrecognized charge

This is more natural than putting it before the noun.

Also, reconocido here behaves like an adjective derived from a past participle:

• reconocer = to recognize
• reconocido = recognized

With no, it means not recognized.

Because it agrees with cargo, which is a masculine singular noun.

Agreement in Spanish:

• un cargo no reconocido → masculine singular
• una transacción no reconocida → feminine singular
• cargos no reconocidos → masculine plural
• transacciones no reconocidas → feminine plural

So the ending changes to match the noun it describes.

Not exactly, although they can be similar in some contexts.

• no reconocido = not recognized
• desconocido = unknown

In banking language, cargo no reconocido is very common and usually means a charge the cardholder does not recognize.

Cargo desconocido is possible, but it sounds more like an unknown charge rather than specifically one you do not recognize from your own statement.

So in fraud or banking contexts, no reconocido is often the most precise choice.

Yes, both are possible, though the nuance changes slightly.

• causa = causes
• provoca = brings about, causes
• genera = generates, gives rise to

Examples:

• La clonación de la tarjeta causa un cargo no reconocido.
• La clonación de la tarjeta provoca un cargo no reconocido.
• La clonación de la tarjeta genera un cargo no reconocido.

All are understandable. Causa is direct and neutral.

The stress is on the last syllable because of the written accent:

• clo-na-CIÓN

A rough pronunciation guide:

• clonación ≈ klo-na-thyon in much of Spain
• In many other Spanish-speaking regions, it is closer to klo-na-syon

The accent mark on ó? Actually here it is on ó? No: clonación is spelled with an accent on ó? Wait, the written form is clonación with the accent on ó? The actual stressed syllable is -ción, and the accent mark is on ó in ción: clonación. That mark tells you the stress falls there.

Yes. Depending on context, Spanish speakers might also say things like:

• La clonación de la tarjeta puede causar un cargo no reconocido.
• La clonación de la tarjeta puede dar lugar a un cargo no reconocido.
• La clonación de la tarjeta puede generar cargos no reconocidos.

These alternatives may sound a bit more natural in explanatory or formal writing, especially if the idea is this can happen rather than this definitely happens.

But the original sentence is grammatically correct and clear.