dousakakunin wo simasu.

It is read:

どうさかくにん を します
dōsa kakunin o shimasu

A natural pronunciation of を in modern Japanese is usually just o.

動作確認 is a noun meaning operation check, function check, or checking that something works properly.

It is made of:

• 動作 = operation, functioning, movement
• 確認 = confirmation, checking, verification

So together, it refers to checking whether a device, system, feature, or machine is working correctly.

を marks the direct object of the verb.

In this sentence:

• 動作確認 = the thing being done
• します = do

So 動作確認をします literally means do an operation check or perform a functionality check.

This is a very common pattern in Japanese:

• 勉強をします = study
• 掃除をします = do cleaning
• 確認をします = do a check / confirm

Japanese often uses a noun + する pattern where English might use a single verb.

Here, 動作確認 is a verbal noun, and adding する turns it into an action:

• 動作確認する = to do a functionality check

In polite form, that becomes:

• 動作確認します
• or with the object marker shown explicitly: 動作確認をします

Both are grammatical. In many cases, を may be omitted with する-verbs, but keeping it can make the structure clearer.

Yes, 動作確認します is also correct and very common.

Both of these work:

• 動作確認をします
• 動作確認します

The version without を is often a little more compact and natural in many everyday and workplace contexts.

The version with を can sound slightly more explicit or structured, which is also common in manuals, procedures, workplace speech, and careful explanations.

します is the polite non-past form of する.

So 動作確認をします is polite and neutral. It is appropriate in situations like:

• speaking to a customer
• workplace communication
• instructions
• formal explanations

Less polite/plain form:

• 動作確認をする

Past polite form:

• 動作確認をしました = did a functionality check

Negative polite form:

• 動作確認をしません = will not do / do not do a functionality check

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

So 動作確認をします could mean:

• I will do a functionality check
• We will do a functionality check
• He/She will do a functionality check
• (Someone) does a functionality check

The exact subject depends on the situation. This is completely normal in Japanese.

します is the non-past polite form. In Japanese, the non-past can mean either:

• present habitual: do
• future: will do

So depending on context, 動作確認をします could mean:

• I do an operation check
• I will do an operation check

Very often in practical contexts, it is understood as I will perform a check or we will perform a check.

Yes, very natural.

動作確認 is especially common in:

• IT
• electronics
• software testing
• machinery
• product support
• manufacturing

For example, you might hear it when someone says they will test whether:

• a device powers on correctly
• software behaves properly
• a feature works as expected
• a machine operates normally

So this is a very practical, real-world expression.

確認 is a broader word meaning confirmation or checking.

動作確認 is more specific: it means checking whether something operates/functions properly.

Compare:

• 確認します = I will check / confirm
• 動作確認します = I will check whether it works properly

So 動作確認 is commonly used when the thing being checked is a machine, system, app, device, or feature.

Yes, a little—but that is normal.

In English, you might expect something like I will perform an operation check on the device. In Japanese, context often supplies the missing details.

For example, in real use, you may see fuller sentences such as:

• 機器の動作確認をします。 = I will check the operation of the equipment.
• アプリの動作確認をします。 = I will check whether the app works properly.

But 動作確認をします by itself is still perfectly natural when everyone already knows what is being checked.

It is somewhere between them, but usually closer to checking that something works.

It does not always imply a deep, full-scale test. Often it means:

• trying it
• running it
• checking its behavior
• confirming it operates normally

So depending on context, translations like these may all work:

• perform a functionality check
• check the operation
• verify that it works
• test its operation

The best English wording depends on the situation.