seikyuukikan wo kakuninsuru.

It is read:

せいきゅうきかん を かくにんする。

• 請求期間 = せいきゅうきかん
• を = pronounced o
• 確認する = かくにんする

In normal writing, it would usually appear without spaces:

請求期間を確認する。

請求期間 is a compound noun made of:

• 請求 = claim, billing, request for payment
• 期間 = period, term, span of time

So 請求期間 usually means something like:

• billing period
• claim period
• period during which billing or claiming applies

The exact English translation depends on context. In a utility bill, it may mean billing period. In insurance or legal paperwork, it could mean claim period.

を marks the direct object of the verb.

Here, the verb is 確認する meaning to confirm / to check, and the thing being checked is 請求期間.

So the structure is:

請求期間 + を + 確認する
= check the billing/claim period

This is a very standard Japanese pattern: object + を + verb

The dictionary form 確認する is commonly used in:

• headings
• instructions
• manuals
• labels
• checklist items
• simple written statements

So this can sound like:

• a neutral action label
• an instruction such as Check the billing period
• a note on a form or screen

If you wanted a polite full sentence, you might say:

請求期間を確認します。

If you wanted a direct command, you might say:

請求期間を確認してください。

Grammatically, it is 確認 + する.

• 確認 is a verbal noun, meaning confirmation or checking
• する turns it into a verb: to confirm / to check

This is a very common pattern in Japanese. Other examples are:

• 勉強する = to study
• 連絡する = to contact
• 予約する = to reserve

So 確認する literally has the structure do confirmation, but in natural English it is simply confirm or check.

Yes. In Japanese, the subject is often omitted when it is obvious from context.

So 請求期間を確認する。 can still be perfectly natural, especially in:

• instructions
• written procedures
• notes
• interface text
• task lists

Depending on context, the omitted subject could be understood as:

• you
• I
• the user
• the staff member
• one

Japanese often leaves this unstated when it is not necessary.

Because the sentence is focused on the action and object, not on stating a topic or explicitly marking a subject.

You could add a topic or subject in a longer sentence, for example:

• 利用者は請求期間を確認する。 = The user checks the billing period.
• 担当者が請求期間を確認する。 = The person in charge checks the billing period.

But when the subject is already understood, Japanese usually leaves it out. That is why the shorter version sounds natural.

The basic order is:

object + を + verb

So:

• 請求期間 = object
• を = object marker
• 確認する = verb

Japanese verbs usually come at the end of the sentence. This is different from English, where the verb often comes earlier.

English: Check the billing period.

Japanese: Billing period + object marker + check

The spaces are probably there only to help learners see the parts more clearly.

In normal Japanese writing, you would usually write:

請求期間を確認する。

Japanese does not normally use spaces between words the way English does.

So the spaced version is a learning aid, not standard formatting.

Not exactly.

確認する means more than just look at. It has the nuance of:

• checking carefully
• verifying
• making sure
• confirming that something is correct

By contrast, 見る simply means to see / to look at.

So:

• 請求期間を見る = look at the billing period
• 請求期間を確認する = check/confirm the billing period

In many practical contexts, 確認する is the more natural choice because it suggests purposeful checking.

Yes. Breaking it down can help:

• 請 = request
• 求 = seek, demand
• 期 = period, time
• 間 = interval, span
• 確 = certain, sure
• 認 = recognize, acknowledge

So the overall idea is something like:

• 請求期間 = the period related to billing or claiming
• 確認する = make sure, verify, confirm

Even if the individual kanji meanings do not give a perfect English translation by themselves, they are useful for remembering the vocabulary.