setuei ga owatta.

It is read:

せつえい が おわった

• 設営 = せつえい
• が = が
• 終わった = おわった

So the full sentence is:

せつえい が おわった。

設営 is a noun. It means something like:

• setting up
• installation
• preparing a site or venue
• putting facilities/equipment in place

It is often used for more formal or large-scale setup, such as:

• event setup
• booth setup
• venue setup
• equipment installation

So in this sentence, 設営 is the thing that has been completed.

が marks the subject of the sentence.

In 設営が終わった, the thing that ended / finished is 設営.

So the structure is basically:

• 設営 = the setup
• が = subject marker
• 終わった = ended / finished

A very literal breakdown is:

• The setup finished

In natural English, you would often say The setup is finished or Setup is done.

Because 終わる is usually an intransitive verb.

That means it describes something ending on its own, rather than someone directly doing the action to an object.

So:

• 設営が終わった = The setup finished / is finished

If you want to say that someone finished the setup, you would more naturally use a transitive expression such as:

• 設営を終えた
• 設営を終わらせた

So the difference is:

• 終わる → something ends
• 終える / 終わらせる → someone finishes something

終わった is the plain past form of 終わる.

• dictionary form: 終わる
• past plain form: 終わった

Even though it is past tense, in Japanese this often corresponds to English:

• finished
• ended
• is done
• has finished

depending on context.

So 設営が終わった can feel like:

• The setup finished
• The setup is done
• The setup has ended

Not directly.

設営が終わった focuses on the state/event of the setup being finished, not on the person who did it.

So it sounds more like:

• The setup is finished
• Setup is done

If you want to focus on the person or team who completed it, Japanese would often use a different structure, for example:

• 私たちは設営を終えた。 = We finished the setup.
• スタッフが設営を終えた。 = The staff finished the setup.

So this sentence is less about who did it and more about the result.

Yes. That is very normal in Japanese.

Japanese often omits information that is clear from context. In this sentence, the speaker assumes the listener already knows what 設営 refers to.

For example, at an event site, someone might simply say:

• 設営が終わった。

That is completely natural if everyone knows the setup work being discussed.

Japanese often leaves out:

• the doer
• the location
• the time
• background context

when those are already understood.

Yes, 設営は終わった is possible.

The difference is in emphasis.

• 設営が終わった

  • neutral identification of what finished
  • often feels like new information
  • answers an implied question such as What finished?

• 設営は終わった

  • marks 設営 as the topic
  • often feels like As for the setup, it’s finished
  • can imply contrast, depending on context

For example:

• 設営は終わったけど、リハーサルはまだです。
  • As for the setup, it’s finished, but rehearsal isn’t yet.

So が is very natural for a simple report of completion, while は is more topic-oriented and can sound contrastive.

Yes, it is natural, especially in contexts like:

• events
• exhibitions
• construction or site work
• stage or venue preparation
• booth installation

It sounds like a straightforward status update.

That said, in casual conversation people might also use other words depending on the situation, such as:

• 準備が終わった。 = The preparations are finished.
• セットアップが終わった。 = The setup is finished.
• 設営は完了した。 = The setup has been completed.

Among these, 設営 has a somewhat formal or work-related feel.

Both can mean that the setup is finished, but the nuance is different.

• 設営が終わった

  • more direct and everyday
  • sounds like a simple report
  • common in speech

• 設営が完了した

  • more formal
  • sounds official, technical, or businesslike
  • common in announcements, reports, or documentation

So:

• 設営が終わった。 = The setup is done.
• 設営が完了した。 = The setup has been completed.

The second one feels more formal and less conversational.

A polite version is:

設営が終わりました。

Breakdown:

• 終わった = plain past
• 終わりました = polite past

This is what you would use when speaking to:

• customers
• superiors
• people outside your close circle
• in formal workplace situations

You could also say:

• 設営が完了しました。 = The setup has been completed.

which is even more formal.

Here are some useful variations:

• 設営が終わる。

  • The setup finishes / will finish

• 設営が終わった。

  • The setup finished / is done

• 設営が終わっている。

  • The setup has finished / is already finished

• 設営が終わっていた。

  • The setup had finished / was already finished

• 設営が終わらない。

  • The setup doesn’t finish / won’t be finished

• 設営がまだ終わっていない。

  • The setup isn’t finished yet

This is a very useful verb pattern to learn because 終わる is common with many nouns:

• 会議が終わった = The meeting ended
• 授業が終わった = Class ended
• 準備が終わった = Preparation is finished

Not exactly.

They overlap, but the nuance is different.

• 準備

  • preparation in general
  • broad and common
  • can include planning, getting things ready, organizing materials, etc.

• 設営

  • physical setup or installation
  • often for a place, event, booth, stage, equipment, or site
  • more specific and somewhat more formal

So if you are talking about actual on-site setup work, 設営 is often the better word.

If you mean preparation in a broader sense, 準備 may be more natural.