hureemusaizu wo kakuninsuru.

を marks the direct object of the verb.

In フレームサイズを確認する, the thing being checked is フレームサイズ, so を shows that フレームサイズ is the object of 確認する.

A simple pattern is:

noun + を + verb

Examples:

• 名前を確認する = confirm a name
• 内容を確認する = confirm the contents
• フレームサイズを確認する = confirm the frame size

Japanese verbs normally come at the end of the sentence.

So the basic order here is:

フレームサイズ → object
を → object marker
確認する → verb

That means Japanese often follows an object + verb pattern, unlike English, which usually uses verb + object.

So even though English says confirm the frame size, Japanese says frame size + object marker + confirm.

確認する is the plain dictionary form.

This form is often used:

• in headings
• in manuals
• in instructions
• in labels or checklist items
• when listing actions in a neutral style

So フレームサイズを確認する。 can sound like:

• a manual step
• a note
• a checklist item
• a simple statement in plain style

If you wanted a polite sentence, you could say:

• フレームサイズを確認します。

If you wanted an explicit instruction, you might also see:

• フレームサイズを確認してください。

It is built from:

• 確認 = confirmation / checking
• する = to do

Together, 確認する means to confirm or to check.

This is a very common pattern in Japanese:

• 勉強する = to study
• 連絡する = to contact
• 確認する = to confirm

So yes, grammatically it is a noun + する verb, but in actual use you can think of it as a normal verb meaning to confirm.

Katakana is commonly used for loanwords from other languages, especially English.

フレームサイズ comes from English frame size, so katakana is natural here.

Katakana is especially common for:

• technical terms
• product features
• computer and design vocabulary
• modern borrowed words

So this sentence has:

• フレームサイズ in katakana because it is a loanword
• 確認 in kanji because it is a native Sino-Japanese word commonly written that way

Yes, it can be, especially in technical, design, software, manufacturing, or product-related contexts.

Japanese often keeps specialized terms in katakana if they come from English. So フレームサイズ is natural when talking about:

• bicycles
• glasses
• images or video
• software interfaces
• product specifications

In other contexts, Japanese might use a different expression depending on what kind of frame is meant, but フレームサイズ itself is not strange.

Japanese often leaves out the subject when it is obvious from context.

So フレームサイズを確認する。 does not explicitly say:

• I confirm the frame size
• You confirm the frame size
• Please confirm the frame size

The exact meaning depends on context.

For example:

• in a manual, it may mean check the frame size
• in notes, it may mean to check the frame size
• in a plain statement, it may mean someone checks the frame size

This kind of omission is very normal in Japanese.

You are right: standard Japanese normally does not use spaces between words.

Normally this would be written as:

フレームサイズを確認する。

Spaces may appear:

• in teaching materials
• in subtitles
• in UI text
• in notes designed for readability
• when someone wants to separate parts clearly for learners

So the spaces here are not wrong in a special context, but they are not the usual way Japanese sentences are written.

They are similar, but not always identical.

確認する often sounds a little more formal and has the nuance of:

• making sure
• verifying
• confirming correctness

チェックする is also common, but it can sound a bit more casual or more directly borrowed from English check.

In many contexts, both may work, but 確認する is very common in manuals, workplaces, and formal instructions.

So フレームサイズを確認する feels like:

• verify the frame size
• make sure of the frame size

rather than just casually looking at it.

Yes. In context, it can function like an instruction, especially in manuals or task lists.

Japanese often uses the dictionary form in procedural writing. For example:

1. 電源を入れる。
2. 設定を確認する。
3. フレームサイズを確認する。

In that kind of writing, the plain form is not rude. It is just a standard instructional style.

If you were speaking directly to someone, you would more often use:

• フレームサイズを確認してください。
• フレームサイズを確認して。 depending on politeness level