L'autobús arriba a l'estació aviat.

L' is the definite article, like the in English.

Here, l' comes from el or la before a vowel sound. Since autobús starts with a vowel, Catalan shortens the article:

• el autobús → l'autobús

So l'autobús means the bus.

Catalan often uses an apostrophe when a word like el or la comes before a noun beginning with a vowel.

So:

• el + autobús → l'autobús
• la + estació → l'estació

This is very common in Catalan and helps the sentence sound smoother.

Arriba is the 3rd person singular present tense of the verb arribar (to arrive).

So:

• arribo = I arrive
• arribes = you arrive
• arriba = he/she/it arrives

In this sentence, l'autobús arriba means the bus arrives.

The preposition a here means to.

So arribar a means to arrive at / to arrive to a place. In natural English, we usually say arrive at the station, but Catalan uses arribar a.

Then:

• a + l'estació = to the station

So arriba a l'estació means arrives at the station.

Catalan normally uses the definite article much more regularly than English in this kind of sentence.

So if you mean the station, you say:

• l'estació

And after a, it becomes:

• a l'estació

Saying a estació would be incorrect here.

Aviat is an adverb meaning soon.

It tells us when the bus arrives.

So the structure is:

• L'autobús = the bus
• arriba = arrives
• a l'estació = at the station
• aviat = soon

Putting aviat at the end is a very normal word order in Catalan.

Catalan often places adverbs like aviat after the verb phrase:

• L'autobús arriba a l'estació aviat.

That said, Catalan word order can be somewhat flexible for emphasis. But in a neutral sentence, this position is completely natural.

Yes. In Catalan, the present tense is often used for things that are scheduled, expected, or happening soon.

So arriba can mean:

• arrives
• is arriving
• sometimes even will arrive

The exact English translation depends on context, but the Catalan present tense is very commonly used this way.

The accent marks show where the stress falls.

• autobús is stressed on the last syllable: au-to-BÚS
• estació is stressed on the last syllable: es-ta-ci-Ó

In Catalan, accent marks are important because they often tell you how to pronounce the word correctly.

Estació is feminine.

That is why the underlying article is la:

• la estació → l'estació

You can see this in other phrases too:

• una estació = a station
• l'estació gran = the big station

Very often, yes. When talking about reaching a destination, Catalan commonly uses arribar a:

• arribar a casa = arrive home
• arribar a Barcelona = arrive in Barcelona
• arribar a l'estació = arrive at the station

So in this sentence, arriba a l'estació is the normal pattern.

The sentence follows a very common pattern:

• Subject: L'autobús
• Verb: arriba
• Place/destination: a l'estació
• Time adverb: aviat

So it is basically:

Subject + Verb + Place + Time

This is a very natural and useful sentence pattern in Catalan.