Cum imber desierit, omnes in solarium ascendent, ut ventum maris sentiant.

Here desierit is most naturally a future perfect indicative, not a subjunctive.

With cum meaning when, Latin often uses the future perfect in the subordinate clause when the main clause is in the future:

• Cum imber desierit, omnes ... ascendent
  = When the rain has stopped, everyone will go up ...

This is a very common Latin pattern:

• subordinate clause: future perfect
• main clause: future

English often translates this simply with present or present perfect in the when-clause, but Latin prefers the future perfect to show that one future action will be completed before another future action happens.

So the sense is:

1. the rain will stop
2. then everyone will go up

Because desierit can also look like a perfect subjunctive form, learners often hesitate here. But with a straightforward temporal cum and a future main verb like ascendent, the future perfect indicative is the expected reading.

Latin could express future time in more than one way, but desierit is especially good here because it emphasizes completion.

• desinet = will stop
• desierit = will have stopped

The sentence is not just saying that rain and going upstairs are both future events. It is saying that the second happens after the first is complete. So desierit is more precise:

• When the rain has stopped, everyone will go up...

That is smoother and more exact than simply when the rain will stop.

Here cum means when in a temporal sense.

It does not mean:

• with (the preposition)
• since
• although

Those are also possible meanings of cum in other contexts, so learners often need to decide from grammar and context.

In this sentence, cum introduces a clause of time:

• Cum imber desierit = When the rain has stopped

Because the clause refers to a future situation, Latin uses the future perfect in the clause.

Imber is nominative singular. It is the subject of desierit.

So the structure is:

• imber = the rain
• desierit = will have stopped / will have ceased

Literally, Latin says something like the rain will have ceased.

Also, imber, imbris is a masculine noun, so if an adjective were added, it would normally agree in the masculine.

Omnes is the nominative plural, meaning all or everyone.

It is the subject of ascendent:

• omnes ... ascendent = everyone will go up / all will go up

Why plural? Because the idea is not every single person as a singular grammatical subject, but all the people as a group.

Compare:

• omnis = every / all in certain singular uses
• omnes = all (people/things) in the plural

In context, omnes is best understood as everyone.

In with the accusative often expresses motion into or onto a place.

So:

• in solarium ascendent = they will go up onto the terrace / sun-deck

This fits naturally with ascendent, since they are moving to that location.

Ad would mean to or toward a place, but in + accusative often gives a stronger sense of entering or moving into the destination itself.

So in solarium is very natural Latin for motion to that place.

Solarium literally has to do with the sun and commonly means something like:

• sun terrace
• roof terrace
• balcony
• sun-deck

In this sentence, it is the place people go up to in order to feel the sea air.

So the image is probably of people going up to an exposed upper area after the rain stops.

Because it is the main action that will happen after the rain stops.

• desierit = will have stopped
• ascendent = will go up

So both actions are in the future, but the first is completed before the second begins.

The future tense in the main clause is straightforward: it tells us what will happen.

This is a purpose clause.

• ut
  • subjunctive = so that, in order that

So:

• ut ventum maris sentiant
  = so that they may feel the sea breeze
  or more naturally, to feel the sea breeze

The full logic is:

• after the rain stops,
• everyone will go up to the terrace,
• in order to feel the sea wind.

Purpose clauses are one of the most common uses of ut.

Because it is in an ut-purpose clause.

A standard Latin rule is:

• ut
  • subjunctive = purpose
• ne
  • subjunctive = negative purpose

So:

• ut ... sentiant = so that they may feel ...

The subjunctive does not necessarily make this doubtful or hypothetical in English. It is simply the normal grammar for expressing purpose in Latin.

Because ventum is the accusative singular of ventus, and it is the direct object of sentiant.

• sentiant = they may feel
• what do they feel? ventum
• maris = of the sea

So:

• ventum maris = the wind of the sea, i.e. the sea breeze

If you used ventus maris, that would be nominative, which would not work as the direct object of sentiant.

Maris is genitive singular of mare.

It depends on ventum and means of the sea:

• ventum maris = the wind of the sea

This is a very common Latin way to connect two nouns, where English often prefers an adjective or a compound expression:

• Latin: ventus maris
• English: sea wind / sea breeze

So the genitive here expresses relationship or source.

Yes, but not in a way that changes the basic meaning.

Latin word order is more flexible than English, so the sentence is arranged in a natural and stylistic way:

• Cum imber desierit: the time-setting comes first
• omnes in solarium ascendent: then the main action
• ut ventum maris sentiant: finally the purpose

This gives a clear progression:

1. when the rain stops
2. everyone will go up
3. to feel the sea wind

Also, placing ventum maris before sentiant keeps the object close to the verb but lets the whole purpose clause end neatly on the verb, which Latin often likes to do.

In other sentences, yes—but probably not here.

Latin has another common use of cum with the subjunctive, often translated:

• when
• since
• although

That construction usually gives background or circumstance, especially in past narration.

But in this sentence, the main clause is future (ascendent), and the clause after cum fits the standard future-time pattern with the future perfect indicative:

• Cum imber desierit ... ascendent

So a learner should understand this as a straightforward temporal clause: When the rain has stopped...

Not very literal. A natural English rendering would be something like:

• When the rain has stopped, everyone will go up to the terrace so that they can feel the sea breeze.

Or even more naturally:

• When the rain stops, everyone will go up to the terrace to feel the sea breeze.

A very literal version such as when the rain will have ceased is grammatically possible in English but sounds less natural. Latin and English handle future time in when-clauses differently, so it is normal to translate idiomatically rather than word-for-word.