La guerra terminó.

In normal Spanish, countable nouns usually need an article or some other determiner. So la guerra is the natural form here.

• La guerra terminó = The war ended
• Guerra terminó would normally sound incomplete or wrong in standard Spanish

Spanish uses articles more often than English, so even when English might sometimes drop them, Spanish often keeps them.

Guerra is a feminine noun, so it takes la.

• la guerra
• una guerra

Like many nouns ending in -a, it is feminine, though that is a pattern, not an absolute rule. You simply have to learn the gender with the noun.

Terminó is the preterite tense, third person singular, from terminar.

Here it means that the action is seen as completed:

• La guerra terminó = the war ended / came to an end

It presents the ending as a finished event.

Because terminó refers to a completed event, while terminaba would usually describe an ongoing past situation, background, or a repeated/habitual action.

• La guerra terminó = the war ended
• La guerra terminaba... = the war was ending / used to end... (depending on context)

In this sentence, the speaker is talking about a clear endpoint, so the preterite terminó is the natural choice.

The accent mark shows both pronunciation and meaning.

• terminó = he/she/it ended or ended
• termino = term / I end in some contexts, depending on pronunciation and structure

In terminó, the stress falls on the last syllable: ter-mi-NÓ.

Without the accent, it would be read differently.

The subject is actually la guerra.

Spanish does not need a separate subject pronoun like it here. English says The war ended, and Spanish simply says La guerra terminó.

Also, terminó is a third-person singular form, which matches la guerra because guerra is singular.

Yes. By itself, terminó can mean:

• he ended
• she ended
• it ended

Spanish verb forms often do not specify the subject as clearly as English does, so the surrounding context tells you what the subject is. In this sentence, la guerra makes it clear that the meaning is the war ended.

In Spain, guerra is pronounced approximately GEH-rra.

A few useful points:

• gue here has a hard g sound, like g in get
• the u is silent in gue
• rr is a strong rolled sound in Spanish

So guerra is roughly GEH-rra, not goo-erra.

Yes. Terminó la guerra is grammatically correct.

The difference is mainly one of word order and focus:

• La guerra terminó = neutral, straightforward
• Terminó la guerra = puts a little more focus on the event of ending, and can sound slightly more dramatic or literary depending on context

Both are natural Spanish.

Yes, you could.

• La guerra terminó = preterite
• La guerra ha terminado = present perfect

In Spain, the present perfect is often used for past events that are seen as connected to the present, especially recent ones. The preterite is commonly used for completed past events viewed more as finished facts.

So both are possible, but they can suggest slightly different perspectives depending on context.

Yes, Se terminó la guerra is also possible and quite common.

It often feels a bit more like:

• The war came to an end
• The war was over

Compared with La guerra terminó, it can sound slightly more expressive or conversational in some contexts. Both are correct; the basic meaning is very similar.