Vectigal in aerarium portatur.

Because vectigal is in the nominative singular, which is the case normally used for the subject.

• vectigal = nominative singular
• It is a neuter noun
• Its dictionary form is also vectigal

So in Vectigal in aerarium portatur, vectigal is the thing being carried.

Vectigal is a third-declension neuter noun.

A learner may notice that it does not look like a first- or second-declension noun such as puella or servus. That is because it belongs to the third declension.

Its basic forms are often given as:

• vectigal, vectigalis = tax, revenue, tribute

Because it is neuter:

• nominative singular: vectigal
• accusative singular: vectigal

So the same form can be nominative or accusative, but here it is nominative because it is the subject.

Because in here governs the accusative to show motion into something.

So:

• in + accusative = into, to, movement toward/into
• in + ablative = in, on, location

Here the idea is that the tax is being carried into the treasury, not simply existing inside it.

That is why Latin uses:

• in aerarium

And aerarium is accusative singular.

You know from the case that follows it.

Latin often uses the same preposition, in, for two different ideas:

• in + accusative = into
• in + ablative = in / on

Since aerarium here is accusative singular, the meaning is into the treasury.

This is a very common pattern in Latin, and English speakers often need to get used to the fact that Latin uses case, not just word choice, to show the difference.

Because portatur is present passive indicative, third person singular of porto.

Breaking it down:

• porta- = verb stem from porto
• -tur = passive ending for he/she/it is ...-ed

So:

• portat = he/she/it carries
• portatur = he/she/it is carried

Since the subject is vectigal, which is singular, the verb is also singular: portatur.

The active form is portat.

Compare:

• portat = carries
• portatur = is carried

So if the sentence were active, it would need someone doing the action, for example:

• Mercator vectigal in aerarium portat. = The merchant carries the tax into the treasury.

But in your sentence, the doer is not named, so Latin uses the passive: Vectigal in aerarium portatur.

Because Latin has no definite or indefinite articles.

English distinguishes between:

• a tax
• the tax

Latin usually does not. A noun like vectigal can mean:

• a tax
• the tax
• sometimes simply tax/revenue

The exact choice in English depends on context. So Latin learners have to remember that the lack of the does not mean the sentence is incomplete.

Because Latin word order is much more flexible than English word order.

A very common neutral Latin order is:

• subject + other elements + verb

So:

• Vectigal = subject
• in aerarium = prepositional phrase
• portatur = verb

Putting the verb last is extremely common in Latin prose. It does not sound unusual in Latin the way it would in English.

Yes. Latin word order is flexible because the endings show each word’s role.

For example, these would mean essentially the same thing:

• Vectigal in aerarium portatur.
• In aerarium vectigal portatur.
• Portatur vectigal in aerarium.

However, the different orders may change emphasis or style.

The version you have is a very straightforward, natural one.

Here aerarium is accusative singular.

Its dictionary form is:

• aerarium, aerarii = treasury

It is a second-declension neuter noun. For second-declension neuter nouns:

• nominative singular ends in -um
• accusative singular also ends in -um

So the form aerarium could be either nominative or accusative in isolation. But after in showing motion, it must be accusative.

Because passive sentences often leave out the agent when it is unknown, unimportant, or obvious from context.

English does this too:

• The tax is carried into the treasury.

You could add the agent in Latin with ab + ablative if needed:

• Vectigal ab ministris in aerarium portatur. = The tax is carried into the treasury by the officials.

But without that phrase, the sentence simply focuses on the action and the thing acted upon.

A learner might want to know the vocabulary entries behind the sentence. They are:

• vectigal, vectigalis = tax, tribute, revenue
• aerarium, aerarii = treasury
• porto, portare, portavi, portatum = carry, bring
• in = in, into

Knowing the dictionary forms helps you recognize:

• declension class of nouns
• gender
• case possibilities
• verb conjugation and voice

Yes, Latin can talk about things like tax, tribute, or revenue as something physically transported, especially in an administrative or historical context.

So portatur is not strange Latin. It can mean that the money, payment, or collected revenue is being brought to the treasury.

English sometimes uses a more abstract phrasing, but Latin is perfectly comfortable with this kind of expression.