Aquest vespre estem mirant el mar a la platja.

It means this evening.

• aquest = this
• vespre = evening

So Aquest vespre estem mirant el mar a la platja starts by setting the time: This evening, we are looking at the sea at the beach.

Because vespre is a masculine singular noun, and aquest has to agree with it.

Catalan demonstratives agree in gender and number:

• aquest = this, masculine singular
• aquesta = this, feminine singular
• aquests = these, masculine plural
• aquestes = these, feminine plural

So:

• aquest vespre = this evening
• but aquesta nit = tonight / this night

Estem mirant is the present progressive: we are looking.

It is formed with:

• estar in the present: estem = we are
• gerund: mirant = looking

So:

• estem mirant = we are looking
• mirem = we look / we are looking

In Catalan, the simple present mirem can often express an action happening now, so mirem el mar could also work. Using estem mirant puts more emphasis on the action being in progress at this moment.

Mirant is the gerund of mirar.

Examples:

• mirar = to look at / to watch
• estic mirant = I am looking
• estem mirant = we are looking

This is similar to the English -ing form, but it is not used in exactly all the same ways as English looking.

Because Catalan often drops the subject pronoun when the verb already makes it clear.

Here, estem clearly means we are, so nosaltres is not necessary.

You could say:

• Aquest vespre estem mirant el mar a la platja.
• Aquest vespre nosaltres estem mirant el mar a la platja.

Both are correct, but the version without nosaltres is more natural unless you want emphasis or contrast.

This is a very common question.

• mirar = to look at, to watch
• veure = to see

So in this sentence, mirant el mar means they are actively directing their attention toward the sea.

Compare:

• Mirem el mar. = We are looking at the sea.
• Veiem el mar. = We can see the sea.

So mirar is the better choice here.

Mar is normally used with the definite article here, so el mar = the sea.

Catalan uses articles very naturally with nouns, often in places where English learners may wonder whether they are needed. In this sentence, el mar is simply the normal way to say the sea.

Also:

• mar is singular
• in modern standard Catalan it is usually treated as masculine here: el mar

Because platja is a feminine noun.

• la platja = the beach

After a, you get:

• a + la platja = a la platja

Catalan only contracts a + el into al:

• a + el parc = al parc

But with la, there is no contraction:

• a la platja, not al platja

It can cover either idea depending on context.

Catalan often uses a where English might choose either at or on. So a la platja can mean:

• at the beach
• on the beach

In this sentence, the natural English translation will depend on the situation, but the Catalan phrase itself is completely normal.

Yes. Catalan word order is fairly flexible, especially with time and place expressions.

The given sentence:

• Aquest vespre estem mirant el mar a la platja.

is very natural.

But you could also say:

• Estem mirant el mar a la platja aquest vespre.
• A la platja estem mirant el mar aquest vespre.

The differences are mainly about emphasis and style, not basic meaning. Putting Aquest vespre first is a very normal way to frame the sentence.

Not exactly.

• vespre = evening
• nit = night

So:

• aquest vespre = this evening
• aquesta nit = tonight / this night

If the action is happening in the evening, vespre is the right word. If it is later, during the night, nit would be more appropriate.

Yes, that is possible in English.

Because mirar can mean to look at or to watch, depending on context, estem mirant el mar could be translated as:

• we are looking at the sea
• we are watching the sea

If the idea is simply that they are gazing at it, looking at the sea is often the clearest translation.