Hodie alveus fluminis altior est, itaque per vadum transire non licet.

Alveus means channel, bed, or course of a river, while flumen means river. So alveus fluminis is more specific than just flumen: it means the river’s channel/bed.

Latin often uses two nouns like this when English would use the X of Y or sometimes just one noun plus another in translation.

Fluminis is genitive singular of flumen.

The genitive often shows possession or close relationship, so alveus fluminis literally means the channel of the river or the river’s channel.

This is a very common Latin pattern:

• porta urbis = the gate of the city
• rex Romae = the king of Rome
• alveus fluminis = the channel of the river

Altior is the comparative form of altus.

• altus = high / deep
• altior = higher / deeper

So the sentence is comparing the river channel to how it normally is or to how it was before. Latin does not always state both sides of the comparison. A comparative can stand by itself when the other standard is understood from context.

So alveus fluminis altior est means something like the river channel is higher/deeper today.

Because Latin does not need quam if the second half of the comparison is only implied.

If you explicitly compare two things, you often use quam:

• altior quam heri = higher than yesterday

But if the comparison is just understood from context, Latin can simply use the comparative adjective alone:

• altior est = it is higher / deeper
• with the sense than before, than usual, or than expected

That is what is happening here.

Yes. Altus can mean both high and deep, depending on context.

This is normal in Latin:

• mons altus = a high mountain
• mare altum = the deep sea

So with a river channel or riverbed, altior is naturally understood as deeper. Context determines which English word is best.

Hodie means today. It is an adverb, so it modifies the whole statement rather than a particular noun.

Here it tells you the time of the situation:

• Hodie alveus fluminis altior est = Today the river channel is deeper

Latin word order is flexible, so hodie is placed first for emphasis, but it could appear elsewhere without changing the basic meaning.

Itaque means and so, therefore, accordingly.

It introduces the result of the first statement:

• the river channel is deeper today,
• therefore crossing at the ford is not allowed / not possible.

So itaque signals a logical consequence.

Vadum is accusative singular after the preposition per.

• per
  • accusative often means through, by way of, or across
• vadum means ford, a shallow place where one can cross water

So per vadum transire means to cross by way of the ford or to go across through the ford.

An English speaker might want to say simply cross the ford, but Latin chooses the expression per vadum transire, focusing on the route taken.

Because it depends on licet.

Licet often means it is permitted or it is allowed, and it commonly takes an infinitive to say what is permitted:

• licet manere = it is permitted to stay
• licet intrare = it is permitted to enter
• non licet transire = it is not permitted to cross

So transire is the infinitive because it is the action governed by licet.

Licet is often used impersonally in Latin. That means it does not have a normal personal subject like he, she, or they. It simply means it is permitted or it is allowed.

So:

• non licet = it is not permitted

If Latin wants to say to someone, it can use the dative:

• mihi non licet = I am not allowed
• nautis non licet = the sailors are not allowed

In your sentence, no dative is stated, so the idea is general: one may not cross, people are not allowed to cross, or simply it is not possible/permitted to cross.

Because the negation is aimed at the idea of permission itself.

• non licet transire = it is not permitted to cross
• licet non transire would mean it is permitted not to cross

Those are very different meanings.

So non is placed with licet because the sentence means that crossing is forbidden or not allowed.

It has two main parts:

1. Hodie alveus fluminis altior est

   • alveus = subject
   • fluminis = genitive modifying alveus
   • altior = predicate adjective
   • est = verb

2. itaque per vadum transire non licet

   • itaque = connective adverb, therefore
   • per vadum = prepositional phrase
   • transire = infinitive
   • non licet = impersonal verb phrase, it is not permitted

So the sentence moves from situation to result: Today the river channel is deeper; therefore crossing at the ford is not allowed.

Latin word order is fairly flexible, because the endings show the grammatical roles.

For example, Latin could rearrange parts of the sentence for emphasis:

• Alveus fluminis hodie altior est
• Per vadum itaque transire non licet
• Hodie altior est alveus fluminis

These would still mean roughly the same thing. The given order is natural and emphasizes hodie first, then gives the consequence with itaque.