Après le retard, nous attendons l’arrivée du train retardé.

Because après normally takes a noun phrase directly, and here le retard refers to a specific delay.

• après le retard = after the delay
• après un retard = after a delay
• après du retard would not be natural here

French uses the definite article very often where English might be less strict about it. In this sentence, le retard points to a particular delay already understood from the context.

They are related, but they are not the same part of speech.

• retard is a noun: delay
• retardé is an adjective or past participle: delayed

So in the sentence:

• Après le retard = after the delay
• le train retardé = the delayed train

A learner may notice that French is using the same idea twice, but with two different grammatical forms.

Because arrivée begins with a vowel sound, and French usually shortens la to l’ before a vowel.

• la arrivée → not correct
• l’arrivée → correct

This is called elision.

Also, arrivée is a feminine noun, so the full article would be la if the next word did not begin with a vowel.

Because du is the required contraction of de + le.

Here, l’arrivée is followed by de to show what is arriving:

• l’arrivée de le train → incorrect
• l’arrivée du train → correct

This is a very common French contraction:

• de + le = du
• de + les = des

So l’arrivée du train simply means the arrival of the train.

Because attendre in French usually takes its object directly, without a preposition.

• English: to wait for something
• French: attendre quelque chose

So:

• nous attendons l’arrivée = we are waiting for the arrival
• not nous attendons pour l’arrivée

This is a very common difference between French and English, and it often causes mistakes for English speakers.

Because most French adjectives are placed after the noun, and retardé follows that normal pattern.

• le train retardé = the delayed train

English usually puts adjectives before the noun, but French often puts them after. Some adjectives can go before the noun, but many do not, and retardé is one that normally comes after.

Yes. Adjectives in French usually agree with the noun they describe in gender and number.

Here, train is:

• masculine
• singular

So the adjective is:

• retardé

If the noun changed, the adjective would change too:

• le train retardé = masculine singular
• la rame retardée = feminine singular
• les trains retardés = masculine plural
• les rames retardées = feminine plural

Yes, and in many everyday situations, le train en retard sounds more natural.

Both can refer to a delayed train, but they are used a little differently:

• un train en retard = a train that is late
• un train retardé = a delayed train

In ordinary speech, French speakers very often use en retard for things that are running late. So l’arrivée du train en retard may sound more idiomatic in many contexts.

It is grammatically correct, but yes, it can sound a bit repetitive because both words come from the same idea of delay.

French allows this, but depending on context, a speaker might choose a smoother version, such as:

• Après ce retard, nous attendons l’arrivée du train.
• Après le retard, nous attendons l’arrivée du train en retard.

So the original sentence is understandable and correct, but it is not the only way to say it.

Because the sentence is describing what we are doing now: we are waiting.

French often uses the simple present where English may use either:

• we wait
• we are waiting

So:

• nous attendons can mean we wait or we are waiting, depending on context

In this sentence, the natural English meaning is likely we are waiting.

Arrivée is the noun formed from the verb arriver.

• arriver = to arrive
• arrivée = arrival

So:

• l’arrivée du train = the train’s arrival / the arrival of the train

This is very common in French: a verb and a related noun often look similar, but they do different jobs in the sentence.