Sine vi pax in urbe manet.

Because sine is a preposition that takes the ablative case. The noun vis (force, violence) is irregular, and its ablative singular form is vi.

So:

• vis = nominative singular
• vi = ablative singular

That is why Latin says sine vi = without force / without violence.

Because in can take two different cases depending on the meaning:

• in + ablative = in / on a place, showing location
• in + accusative = into / onto a place, showing motion toward

Here the sentence describes where peace remains, not movement into the city, so Latin uses the ablative:

• in urbe = in the city
• in urbem = into the city

Pax is in the nominative case, which is the case normally used for the subject of the sentence. Also, the verb manet is third person singular, so it matches a singular subject like pax.

The other noun phrases are introduced by prepositions:

• sine vi
• in urbe

Those are not the subject.

So pax is the word doing the action of remaining.

Manet comes from maneo, manere, which means remain, stay, continue, or abide.

Manet is:

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

So it means he/she/it remains or stays.
With pax as the subject, it means peace remains or peace stays.

Latin does not have articles like English the and a/an. Whether a noun is definite or indefinite usually has to be understood from context.

So:

• pax can mean peace
• in urbe can mean in the city or in a city, depending on context

English has to choose an article, but Latin often does not.

Yes. Latin word order is much more flexible because the endings show how words function in the sentence.

In English, changing the order often changes the meaning. In Latin, the endings usually keep the meaning clear. So this sentence could be rearranged in other ways, such as:

• Pax sine vi in urbe manet
• In urbe pax sine vi manet

The basic meaning would stay much the same, though the emphasis might shift. Putting pax early can give it prominence.

Pax is a third-declension feminine noun. Its dictionary form is:

• pax, pacis = peace

In this sentence, pax is nominative singular, because it is the subject.

If there were an adjective describing it, that adjective would have to agree with pax in gender, number, and case.

Vis is a broad word. Depending on context, it can mean:

• force
• violence
• strength
• power

After sine, the phrase sine vi often suggests without force or without violence. The exact nuance depends on the wider context.

Yes. Both are prepositions, and Latin prepositions regularly govern specific cases.

In this sentence:

• sine takes the ablative → sine vi
• in takes the ablative here because it shows location → in urbe

This is an important pattern in Latin: when you learn a preposition, you should also learn which case or cases it uses.

Yes. Remains is often the most natural translation here. Stays is also possible, but remains usually sounds a little closer to the sense of maneo in a sentence like this.

So depending on style, you might understand manet as:

• remains
• stays
• endures
• continues

All of those reflect the core idea of continuing in place or condition.