Aquest vespre soparem a la terrassa si encara fa bon temps.

Aquest vespre means this evening. It refers to the early-to-mid evening period, often around the time people eat dinner.

Aquesta nit means tonight, but nit is more specifically night, so it can sound a bit later or broader in time.

In this sentence, vespre fits well because it is talking about dinner: soparem.

Because vespre is a masculine noun in Catalan.

So:

• aquest = this, masculine singular
• aquesta = this, feminine singular

Since vespre is masculine, the correct form is aquest vespre.

Soparem is the 1st person plural future form of sopar (to have dinner / to eat dinner).

So:

• sopar = to have dinner
• soparem = we will have dinner

The ending -em here is part of the future form for nosaltres in this verb.

Yes, very often in everyday Catalan you could hear sopem instead of soparem if the time reference is already clear.

So both can work:

• Aquest vespre soparem... = a clear future form
• Aquest vespre sopem... = present used with future meaning

Using soparem makes the future especially explicit.

Here a is the normal preposition used for location before many places.

So a la terrassa means on the terrace or at the terrace, depending on how English would naturally say it.

Catalan often uses a where English might use in, at, or on:

• a casa = at home
• a l’escola = at school
• a la terrassa = on the terrace

The article la is there because terrassa is feminine singular.

Because in Catalan, after si meaning if, you normally use the present tense for a real future condition.

So:

• si encara fa bon temps = if the weather is still nice

This is similar to English:

• If the weather is still nice, we’ll eat outside not
• If the weather will still be nice... in standard usage

So Catalan does not usually say si farà bon temps in this kind of sentence.

Here encara means still.

So si encara fa bon temps means if the weather is still nice.

Encara is a very common word and can have a few related meanings depending on context, such as still, yet, or even even in some expressions. In this sentence, the meaning is clearly still.

Yes, literally it uses the verb fer (to do / to make), but fa bon temps is simply the normal Catalan way to say the weather is nice.

This is an idiomatic weather expression:

• fa bon temps = the weather is nice / it’s good weather
• fa mal temps = the weather is bad
• fa fred = it’s cold
• fa calor = it’s hot

So even though the literal structure looks unusual to an English speaker, it is completely standard Catalan.

Because bo changes form before a masculine singular noun.

The masculine singular adjective has two forms:

• bo
• bon before the noun

Since temps is a masculine singular noun, Catalan says:

• bon temps

Compare:

• un dia bo = a good day
• bon temps = good weather

So bon is the form used before the noun here.

Here it means weather.

In Catalan, temps can mean both:

• time
• weather

You understand the meaning from context. In the expression fa bon temps, it definitely means weather.

Yes, the si clause could come first.

For example:

• Si encara fa bon temps, aquest vespre soparem a la terrassa.

Both orders are correct.

The version with Aquest vespre first puts the focus first on when the action will happen. The version with Si encara fa bon temps first emphasizes the condition.

Yes, they are cognates and mean the same kind of thing: terrace.

But the Catalan spelling is different:

• Spanish: terraza
• Catalan: terrassa

The double ss is normal in Catalan spelling.

A very natural spoken version could be:

Aquest vespre sopem a la terrassa si encara fa bon temps.

This uses the present tense sopem with future meaning, which is very common in conversation.

The original sentence with soparem is also completely natural; it is just a bit more explicitly future.