toutyaku no zikan ga kawatta ka douka, tenin ni kakuninsite kudasai.

の links one noun to another, like of in English.

So:

到着の時間 = the time of arrival / arrival time

It shows that 時間 is being specified by 到着.

A very common alternative is 到着時間, where the two nouns are combined into a compound noun. Both are understandable.

• 到着の時間 feels a little more separated and explicit
• 到着時間 feels more compact and common

Because in 到着の時間が変わった, the time is the thing that changed.

The verb 変わる is intransitive, so the thing that changes is marked with が:

• 時間が変わる = the time changes

Using を would be wrong here because 変わる does not take a direct object.

Using は is possible in some contexts, but it would change the nuance by making 時間 the topic or adding contrast. が is the most neutral and natural choice here.

In Japanese, the past form often means that a change has already happened by the time you are talking about it.

So 変わったかどうか means:

• whether it changed
• whether it has changed

It does not necessarily sound as distant as the English simple past sometimes does. The idea is that you are checking whether the arrival time is already different now.

Because Japanese usually uses the plain form inside subordinate clauses, even when the overall sentence is polite.

So this is natural:

• 変わったかどうか、確認してください。

The politeness is shown at the end with 確認してください.

If you say 変わりましたかどうか, it sounds unnatural or overly formal inside that clause. This is a very common rule in Japanese:

• inside the sentence: plain form
• end of the sentence: polite form, if needed

かどうか means whether or not.

It is used to turn a yes/no question into an embedded clause.

So:

• 変わったかどうか = whether it changed / whether or not it changed

This is very common when reporting or checking yes/no information.

Compare:

• 来るかどうか分かりません。 = I don’t know whether he will come.
• 正しいかどうか確認する。 = confirm whether it is correct.

Sometimes yes, but かどうか is clearer and more explicitly means whether or not.

For example:

• 変わったか確認してください。
• 変わったかどうか確認してください。

Both can work, but かどうか makes the yes/no uncertainty more explicit. It is especially common in careful or standard written Japanese.

The full clause 到着の時間が変わったかどうか is the content being confirmed.

In many cases, Japanese can omit the particle を before 確認する, especially when the clause comes right before the verb.

So these are both possible:

• 到着の時間が変わったかどうか、店員に確認してください。
• 到着の時間が変わったかどうかを、店員に確認してください。

The version without を sounds natural and is very common. The version with を is a little more explicit.

Because 店員に marks the person you are checking with.

Here, the thing being confirmed is the content clause:

• 到着の時間が変わったかどうか

And the person you ask or verify it with is:

• 店員に

So:

• 店員に確認する = confirm with the clerk

If you said 店員を確認する, that would mean something more like check the clerk or verify the clerk, which is not the intended meaning.

Not exactly.

• 聞いてください = please ask / please listen
• 確認してください = please check / please verify / please confirm

確認してください suggests making sure the information is correct. It sounds more precise than just asking.

So in this sentence, the speaker is not just saying ask the clerk casually. They are saying please check with the clerk and make sure whether the arrival time has changed.

Because these two verbs are different:

• 変わる = to change, to be changed (intransitive)
• 変える = to change something (transitive)

Here the sentence focuses on the arrival time itself changing:

• 時間が変わった = the time changed

If you used 変える, you would need a person or agent doing the changing:

• 店が時間を変えた = the store changed the time

So 変わった is the natural choice here.

It is natural enough, but it is not the only option.

Common alternatives are:

• 到着時間 = arrival time
• 到着時刻 = arrival time, more formal

Compared with those:

• 到着の時間 sounds a little more expanded
• 到着時間 sounds more compact and very common
• 到着時刻 sounds more formal or official

So the original phrase is fine, but in many real-life situations you might also see 到着時間が変わったかどうか.

Because Japanese normally puts subordinate or content clauses before the main verb.

So the structure is:

• [what to confirm]
  • [who to confirm with]
    • 確認してください

That gives:

• 到着の時間が変わったかどうか、店員に確認してください。

This is normal Japanese word order. English often puts the main verb earlier, but Japanese tends to build up the information first and then finish with the action.

Also, the comma here is mainly for readability. It helps separate the long clause from the main request, but it is not absolutely required.