Learn Hardcore Spanish (Spain): La entrega del pedido llegó con retraso, pero no fue un problema. - The delivery of the order arrived late, but it was not a problem.

La entrega del pedido = the delivery of the order (focus on the delivery event).
El pedido = the order / parcel / goods (focus on the thing you bought).

Both are possible, but they focus on different aspects:

La entrega del pedido llegó con retraso…
Emphasis: the delivery process was late.
El pedido llegó con retraso…
Emphasis: the package/order itself arrived late.

In everyday speech, a Spaniard could easily say either, depending on what they want to highlight.

What does del mean in la entrega del pedido?

Del is the contraction of de + el.

de + el pedido → del pedido

You must use the contraction in standard Spanish; you cannot write de el pedido. This contraction happens only with de + el → del and a + el → al.

Why is it llegó and not llegaba or ha llegado?

Llegó is the preterite (pretérito indefinido), used for a completed past event viewed as a single whole:

La entrega del pedido llegó con retraso…
The delivery arrived late (you see it as one finished event in the past).

Other options are possible with slightly different nuances:

La entrega del pedido ha llegado con retraso…
Present perfect (pretérito perfecto). In Spain, this often suggests a link to the present (e.g. you’re talking about it the same day, it still feels “current”).
La entrega del pedido llegaba con retraso…
Imperfect (imperfecto). This would normally sound odd here unless you’re setting a scene or describing something habitual:
- La entrega del pedido llegaba siempre con retraso.
  The delivery of the order always used to arrive late.

In the original sentence, a single, completed past event is being reported, so llegó is the natural choice.

Why is it llegó con retraso and not llegó tarde? Are they both correct?

Both are correct, but they differ slightly in tone and nuance:

Llegó tarde
Very common, neutral, everyday: it arrived late.
Llegó con retraso
Slightly more formal/technical. Often used for trains, planes, deliveries, scheduled services, etc.

Examples:

El tren llegó con retraso.
El pedido llegó tarde.

You could definitely say:

La entrega del pedido llegó tarde, pero no fue un problema.

It sounds a bit more informal and everyday than con retraso.

Could you say vino con retraso instead of llegó con retraso?

You could, but llegar is much more natural here.

Llegar = to arrive (neutral, used for packages, trains, people, etc.)
Venir = to come, to come (to where the speaker is), often with more of a sense of movement towards the speaker.

For deliveries, messages, transport, etc., llegar is the default verb:

El paquete llegó hoy.
La factura llegó ayer.

Vino con retraso would be understood, but it sounds less standard in this context.

Why is it la entrega (feminine) but el pedido and el problema (masculine)?

Noun gender in Spanish is largely grammatical, not logical, and must be memorised. Some patterns help:

Nouns ending in -a are often feminine: la entrega, la casa, la mesa.
Nouns ending in -o are often masculine: el pedido, el libro, el coche.

However, there are exceptions, like el problema, which ends in -a but is masculine (explained below). The key point here:

la entrega → feminine
el pedido → masculine
el problema → masculine

You just learn each noun with its article.

Why is problema masculine (el problema) even though it ends in -a?

Problema is one of a group of masculine nouns ending in -ma that come originally from Greek (via Latin). Many of these are masculine:

el problema
el tema (topic, theme)
el sistema (system)
el programa (program)
el clima (climate)

So we say:

el problema, un problema
no fue un problema

You must treat problema as masculine in articles and adjectives:

un problema serio, el problema principal, etc.

Why is it no fue un problema and not no era un problema?

This is a choice between preterite (fue) and imperfect (era):

no fue un problema
→ It wasn’t a problem (in that particular, completed situation).
You see it as a specific past event whose outcome is known: the delivery was late, but that fact turned out not to be a problem.
no era un problema
→ It wasn’t a problem (as a more ongoing / background state).
You’d use this if you are describing a general or repeated situation, or setting a background:
- La entrega del pedido llegaba con retraso, pero no era un problema.
  The delivery of the order used to arrive late, but it wasn’t (generally) a problem.

In the original, we’re talking about one specific occasion, so fue is the natural tense.

Could you say no fue problema without un?

Yes, you can also say:

…pero no fue problema.

Both are correct:

no fue un problema
no fue problema

The version without the article sounds a bit more concise and idiomatic, similar to English it was no problem.

Nuance:

no fue un problema = it wasn’t a problem (fairly neutral).
no fue problema = it was no problem at all (often a bit more informal / relaxed-sounding).

In many contexts, they’re interchangeable.

Can I replace no fue un problema with a shorter expression, like no hubo problema?

Yes, that’s very natural. Alternatives include:

La entrega del pedido llegó con retraso, pero no hubo problema.
= The delivery arrived late, but there was no problem.

Other common variants in Spain:

…, pero no supuso un problema.
…, pero no pasó nada. (more colloquial: “…but nothing happened / it was fine.”)

All of these convey essentially the same idea.

Can I refer back to la entrega del pedido with lo in pero no lo fue?

Yes, and this is a good structure to know:

La entrega del pedido llegó con retraso, pero no fue un problema.
La entrega del pedido llegó con retraso, pero no lo fue.

In no lo fue, lo doesn’t literally stand for a masculine noun; instead, it refers to the idea of ser un problema (being a problem) as a whole.

That’s why you use lo, not la:

…pero no lo fue. = but it wasn’t (a problem).

Using lo in this way is very common after ser to replace a whole description:

¿Fue difícil? – No, no lo fue.
¿Fue caro? – Sí, lo fue.

Is this sentence more formal or informal? Would a Spaniard say it like this?

The sentence is neutral and would sound natural in Spain, for example in:

An email from customer service.
A description of a past delivery.
A conversation where someone is explaining what happened.

It is neither very casual nor very formal. In everyday speech, a Spaniard might also say something like:

El pedido llegó tarde, pero no fue problema.
El pedido llegó tarde, pero no hubo problema.

The original version is perfectly normal, especially in slightly more careful or written language.