Omnes mirantur quam cito nebula super flumen veniat.

Here omnes means everyone or all people.

Grammatically, omnes is nominative plural, so it is the subject of mirantur. Latin often uses a plural adjective by itself to mean all people when the noun is understood.

So:

• omnes mirantur = everyone is amazed / all people wonder

It is plural in form, even if English often translates it with the singular idea everyone.

Because its subject, omnes, is plural.

• omnes = all people
• mirantur = they wonder / they are amazed

So the agreement is straightforward:

• plural subject → plural verb

Even if you translate omnes as everyone, Latin is still thinking in terms of all persons, so the verb is plural.

Because miror, mirari is a deponent verb.

A deponent verb:

• has passive forms
• but an active meaning

So mirantur literally looks like a passive form, but it actually means:

• they wonder
• they are amazed

not they are wondered.

This is very common in Latin, and miror is one of the standard deponent verbs students learn early.

Quam cito means how quickly.

In this sentence:

• cito = quickly
• quam = how, introducing the question-like idea

Together they form an indirect question:

• quam cito nebula super flumen veniat = how quickly the mist comes over the river

So quam here is not the relative pronoun than/which, but an interrogative word used with an adverb.

Because quam cito nebula super flumen veniat is an indirect question.

Latin normally uses the subjunctive in indirect questions. Since the sentence is about what people wonder, not a direct statement, Latin puts the verb of that subordinate clause into the subjunctive:

• direct question: Quam cito nebula super flumen venit? = How quickly does the mist come over the river?
• indirect question: Omnes mirantur quam cito nebula super flumen veniat. = Everyone wonders how quickly the mist comes over the river.

So veniat is subjunctive because the clause depends on mirantur.

Veniat is present subjunctive, third person singular.

In an indirect question after a present main verb like mirantur, the present subjunctive usually shows action happening at the same time as the main verb.

So the sense is something like:

• how quickly the mist is coming
• how quickly the mist comes

Both are reasonable English renderings depending on context.

Nebula is nominative singular.

It is the subject of veniat:

• nebula veniat = the mist comes

So the sentence has:

• main clause subject: omnes
• main clause verb: mirantur
• subordinate clause subject: nebula
• subordinate clause verb: veniat

Because super can take different cases depending on the sense.

Here super takes the accusative (flumen) because the idea is one of movement over/toward/across the river.

• super flumen = over the river

If Latin wanted to stress location rather than motion, the ablative could be used in some contexts:

• super flumine = above/on/over the river in a more static sense

In this sentence, the mist is understood as coming over the river, so the accusative fits well.

Flumen is accusative singular.

Its dictionary form is:

• flumen, fluminis = river

Here it is accusative because it follows super in a phrase expressing motion:

• super flumen = over the river

Latin word order is much more flexible than English word order because Latin shows grammatical relationships mainly through endings, not position.

A more English-like order might be:

• Omnes mirantur nebula quam cito super flumen veniat

But Latin can place words for emphasis or rhythm. In the given sentence:

• Omnes mirantur sets up the main idea first
• quam cito comes early in the subordinate clause, highlighting how quickly
• super flumen is placed before veniat, which is also natural Latin style

So the word order is not random; it is just less fixed than in English.

The verb miror can have a range of meanings such as:

• wonder at
• be amazed at
• admire

In this sentence, because it is followed by an indirect question (quam cito ... veniat), the sense is clearly wonder or be amazed at how.

So:

• Omnes mirantur quam cito... = Everyone wonders / is amazed at how quickly...

Admire would be less natural in this particular construction.

Not exactly. It is an indirect question, not a direct one.

A direct question would stand on its own:

• Quam cito nebula super flumen venit?
• How quickly does the mist come over the river?

But here the question is reported as the object of mirantur:

• They wonder how quickly the mist comes over the river

That is why Latin uses the subjunctive veniat instead of the indicative.

A useful breakdown is:

• Omnes — nominative plural, subject, everyone / all people
• mirantur — 3rd person plural present deponent, wonder / are amazed
• quam cito — how quickly
• nebula — nominative singular, subject of the subordinate verb, the mist
• super flumen — prepositional phrase, over the river
• veniat — 3rd person singular present subjunctive, comes / is coming

So the structure is:

• main clause: Omnes mirantur
• indirect question: quam cito nebula super flumen veniat