El bloqueo temporal afecta a la tarjeta de débito.

Because bloqueo is a singular masculine noun, so it takes el when you mean the blocking / the temporary block.

• el bloqueo = the block
• un bloqueo = a block

In this sentence, it refers to a specific situation, so el is used.

Also, in Spanish, articles are often used more regularly than in English, so where English might sometimes sound natural without the, Spanish often still uses el / la / los / las.

Bloqueo is a noun, while bloquear is a verb.

• bloquear = to block
• bloqueo = block, blocking, or freeze depending on context

In this sentence, the subject is a thing: El bloqueo temporal. So Spanish needs the noun bloqueo, not the verb.

This is a very common pattern in Spanish:

• pagar → pago
• cobrar → cobro
• bloquear → bloqueo

Because in Spanish, adjectives usually come after the noun.

• bloqueo temporal = temporary block
• tarjeta nueva = new card
• problema técnico = technical problem

Putting the adjective after the noun is the normal word order. Sometimes adjectives can go before the noun, but that often changes the tone or meaning slightly. Here, bloqueo temporal is the standard, natural order.

Here it means temporary.

That can be confusing because temporal can also be a noun meaning storm or bad weather event in other contexts:

• un temporal = a storm / spell of severe weather

But in bloqueo temporal, it is clearly an adjective describing bloqueo, so it means temporary.

Because the verb afectar is commonly used with a before the thing or person affected.

So:

• afectar a alguien
• afectar a algo

Examples:

• Esto afecta al cliente.
• La avería afecta a la cuenta.
• El bloqueo afecta a la tarjeta.

Even though English says affects the card without a preposition, Spanish normally says afecta a la tarjeta.

Not exactly.

The personal a is the a used before a specific person as a direct object:

• Veo a María.

But in afecta a la tarjeta, tarjeta is not a person. Here, the a is part of how the verb afectar is commonly constructed: afectar a algo/alguien.

So for a learner, the easiest way to remember it is:

• learn afectar as afectar a

Because Spanish usually uses the article when referring to a specific noun.

• la tarjeta = the card

So:

• afecta a la tarjeta de débito = it affects the debit card

Leaving out la would usually sound incomplete or unnatural here.

Also notice that a + la stays a la.
Only a + el contracts:

• a + el = al
• a + la = a la

Because Spanish often uses de + noun where English uses a noun as an adjective.

English:

• debit card
• credit card

Spanish:

• tarjeta de débito
• tarjeta de crédito

This is one of the most common structural differences between English and Spanish. Spanish often prefers:

• noun + de + noun

rather than stacking nouns together like English does.

The accent mark shows where the stress goes: DÉ-bi-to.

Without the written accent, Spanish stress rules would make you pronounce it differently. The accent tells you clearly that the stress is on the first syllable.

So:

• débito → stress on dé

This is important both for pronunciation and spelling.

A natural Spain pronunciation would be roughly:

el blo-KE-o tem-po-RAL a-FEK-ta a la tar-HE-ta de DE-bi-to

A few useful notes:

• bloqueo has three syllables: blo-que-o
• temporal is stressed on the last syllable: tem-po-RAL
• afecta is stressed on fec
• In much of Spain, z and soft c are pronounced with a th sound, but there is no z or soft c in this sentence
• In most of Spain, j in tarjeta sounds strong, like the ch in Scottish loch or a throaty English h

Yes. That is grammatically correct, but it changes the structure and emphasis.

• El bloqueo temporal afecta a la tarjeta de débito.
  Focus: the block is doing the affecting.

• La tarjeta de débito está afectada por el bloqueo temporal.
  Focus: the card is in an affected state.

The original sentence is more direct and probably more natural in many practical or banking contexts.

It is a very common and natural combination, especially in technical, banking, and customer-service language.

You will often see similar combinations such as:

• suspensión temporal
• error temporal
• restricción temporal
• bloqueo permanente

So while it is not an idiom you must memorize as one inseparable chunk, it is definitely a normal collocation in Spanish.

Sometimes, yes. If the context is already clear, people may simply say:

• la tarjeta

For example:

• El bloqueo temporal afecta a la tarjeta.

But if you need to be precise, especially in banking or support contexts, la tarjeta de débito is better because it distinguishes it from:

• tarjeta de crédito
• tarjeta prepago
• tarjeta bancaria