Civis ad tribum et centuriam pertinet.

Here civis is nominative singular, because it is the subject of pertinet.

A learner may notice that civis can also be the genitive singular in some contexts, since the nominative and genitive have the same form. But in this sentence, the syntax makes it clear that civis is the subject: the citizen belongs / pertains.

They are accusative because they are governed by the preposition ad, and ad normally takes the accusative case.

So:

• ad tribum
• ad centuriam

This is a common Latin pattern. With pertinere ad, the idea is to belong to, to pertain to, or to be assigned to something.

Because the noun is tribus, a fourth-declension feminine noun, and its accusative singular is tribum.

Its forms are a little tricky because the dictionary form ends in -us, which often makes English speakers expect a masculine second-declension pattern. But tribus is not second declension.

So here:

• dictionary form: tribus
• accusative singular: tribum

That is exactly the form needed after ad.

Pertinet is:

• third person singular
• present tense
• active voice
• indicative mood

from the verb pertinere.

So it means he/she/it belongs, pertains, or is assigned. Since the subject civis is singular, the verb is singular too.

Because one preposition can govern two coordinated words if both have the same relationship to it.

So:

• ad tribum et centuriam

means

• to a tribe and a century

Latin does not need to repeat the preposition:

• ad tribum et ad centuriam

would also be understandable, but it is less compact and would usually add a bit more emphasis or separation.

Et connects tribum and centuriam.

Both nouns are parallel objects of ad:

• ad tribum
• ad centuriam

So the structure is basically:

• Civis = subject
• ad tribum et centuriam = prepositional phrase
• pertinet = verb

Because Latin word order is much more flexible than English word order, and it is very common for the verb to come at or near the end.

This sentence has a very normal Latin arrangement:

• subject first: Civis
• then the related phrase: ad tribum et centuriam
• then the verb: pertinet

English usually requires a more fixed order, but Latin often uses word order for emphasis, rhythm, or style rather than basic grammatical function.

Because Latin has no articles.

So civis can mean:

• a citizen
• the citizen

and tribum / centuriam can mean:

• a tribe / a century
• the tribe / the century

The exact sense depends on context. In a general statement like this, English often translates it as a citizen belongs to a tribe and a century.

No. Here centuria does not mean a period of one hundred years.

In Roman usage, a centuria was a military or voting division. In this sentence, it refers to a Roman civic classification, not time.

That is important because an English speaker may see centuriam and immediately think of the time word century, but that would be misleading here.

Not exactly. Although tribus is the source of the English word tribe, in this sentence it refers to a Roman tribe, meaning a political or administrative division of citizens.

So this is not primarily about ethnicity or family background. It is about Roman civic organization.

Yes. Pertinere ad often means to pertain to, to relate to, or to belong to in a broad sense.

In this sentence, because the context is Roman civic membership, belongs to or is assigned to is a natural translation. But the underlying Latin verb is wider in meaning than simple ownership. It expresses connection, relation, or membership.