sizyou wo suru.

It is read しじょうをする.

• 試乗 = しじょう
• を = the object particle, pronounced お
• する = to do

So the whole phrase is しじょうをする.

試乗 is a noun, but it is also the kind of noun that can combine with する to make a verb-like expression.

This type is often called a verbal noun or suru-noun.

So:

• 試乗 = a test ride / a test drive
• 試乗する = to test ride / to test drive

This pattern is very common in Japanese:

• 勉強する = to study
• 運動する = to exercise
• 質問する = to ask a question
• 試乗する = to take a test ride / test drive

Because 試乗 is being treated as the object of する.

Literally, the structure is something like:

• 試乗 = test ride / test drive
• をする = do

So 試乗をする is literally do a test drive or do a test ride.

That said, in modern Japanese, with many suru-nouns, the shorter form without を is more common:

• 試乗する

So both are grammatical, but 試乗する is usually more natural and more compact.

Yes, in many cases 試乗する sounds more natural.

Compare:

• 試乗する
• 試乗をする

Both can be correct, but 試乗する is often the default way to say it.

The version with を may appear when:

• the speaker wants a slightly more deliberate or formal structure
• the noun is being modified
• the rhythm of the sentence makes を feel natural

For example:

• 新型バイクを試乗する。 = to test ride the new model bike
• 試乗をする前に説明を聞く。 = listen to the explanation before doing a test ride

So for everyday learning, it is good to know that 試乗する is the form you will probably see most often.

Yes, it can be a complete sentence in Japanese, but it is a very context-dependent one.

Japanese often leaves out the subject when it is understood. So 試乗をする。 could mean:

• I will take it for a test drive.
• We do test rides.
• To take a test ride.
  depending on context

Also, する is in the plain non-past form, which can mean:

• present/habitual: do / does
• future: will do

So by itself, 試乗をする。 is grammatically complete, but in English you would usually need more context to know the exact meaning.

They are related, but not the same.

• 試乗 = a test ride / test drive, usually trying a vehicle before deciding whether to buy it
• 運転 = driving in general

So:

• 車を運転する = drive a car
• 車を試乗する = test drive a car

Also, 試乗 is not limited to cars. It can be used for things like:

• cars
• motorcycles
• bicycles
• sometimes other rideable vehicles

The key idea is trying it out.

Yes, absolutely. In fact, that is very common.

Examples:

• 車を試乗する = to test drive a car
• バイクを試乗する = to test ride a motorcycle

This is often more informative than just saying 試乗する, because it tells you what is being test-ridden.

Be careful not to overthink the particles here. Japanese allows expressions like:

• 車を試乗する

Even though 試乗 already contains the idea of riding, this is a normal and natural expression.

Change する to します.

• 試乗をする。 = plain
• 試乗をします。 = polite

More commonly, you will often hear:

• 試乗します。

Examples:

• この車を試乗します。 = I will test drive this car.
• 試乗できますか。 = Can I take it for a test drive?
• 試乗したいです。 = I want to take it for a test drive.

You conjugate する.

Using the shorter and more common form 試乗する:

• 試乗する = do a test drive / will test drive
• 試乗した = did a test drive
• 試乗しない = do not test drive / will not test drive
• 試乗しなかった = did not test drive

Polite forms:

• 試乗します
• 試乗しました
• 試乗しません
• 試乗しませんでした

You can do the same with 試乗をする, but in practice learners will more often use the forms without を.

Although it is written を, the particle is normally pronounced お in modern Japanese.

So:

• 試乗をする

sounds like:

• しじょう お する

not like a strong wo sound.

Many textbooks still write it as wo in romanization because that reflects the spelling, but the actual pronunciation is usually just o.

Yes.

• 乗る means to ride / to get on
• 試乗する means to take something for a test ride / test drive

So 乗る is general, while 試乗する specifically includes the idea of trying the vehicle out, often before buying.

Compare:

• バイクに乗る = ride a motorcycle
• バイクを試乗する = test ride a motorcycle

So if the situation is about trying a vehicle at a dealership or event, 試乗する is the right word.

No, normal Japanese writing usually does not use spaces between words.

The standard written form would be:

• 試乗をする。

or more commonly:

• 試乗する。

Spaces are sometimes added in teaching materials to help beginners see the word boundaries, but they are not normally used in everyday Japanese text.