Druhé auto jezdí na naftu.

Czech has no articles, so there is no separate word for the or a/an.

So Druhé auto can mean things like:

• the second car
• a second car
• sometimes the other car

The exact interpretation depends on context.

Because auto is a neuter singular noun, and adjectives must agree with the noun they describe.

So:

• masculine: druhý
• feminine: druhá
• neuter: druhé

Since auto is neuter, the correct form is druhé auto.

Most basically, druhé means second.

Depending on context, druhé auto can mean:

• the second car
• the other car (for example, when comparing two cars)

If you just want to say another car, Czech more often uses jiné auto.

In Czech, nouns have grammatical gender: masculine, feminine, or neuter.

Auto is neuter. That is simply the gender this noun has in Czech, and learners need to memorize it with the word.

A useful clue is that many neuter nouns end in -o, and auto does too.

Jezdí is from the verb jezdit.

Here it means something like:

• goes
• drives
• runs
• is used/driven regularly

With vehicles, jezdit na naftu means to run on diesel.

So the sentence is talking about how the car normally operates, not about one single trip.

This is a very common question.

• jezdit = to go/drive/ride habitually, repeatedly, regularly
• jet / jede = to go/drive right now or on one particular trip

So:

• Druhé auto jezdí na naftu. = The second car runs on diesel / is diesel-powered.
• Auto jede do Prahy. = The car is going to Prague.

In this sentence, the idea is a general characteristic of the car, so jezdí is the natural choice.

It can be either singular or plural in the present tense.

• auto jezdí = the car runs/drives
• auta jezdí = the cars run/drive

Czech often uses the same form here, so you know the number from the subject:

• auto = singular
• auta = plural

In this sentence, jezdí is singular because auto is singular.

Because after na in this expression, Czech uses the accusative case.

The basic form is:

• nafta = nominative

But after na in jezdit na naftu, it changes to:

• naftu = accusative

So:

• nafta = diesel
• na naftu = on diesel / using diesel

With fuels and energy sources, Czech often uses na + accusative to mean powered by, running on, or using.

Examples:

• jezdit na benzín = run on petrol
• jezdit na naftu = run on diesel
• jezdit na plyn = run on gas
• jezdit na elektřinu = run on electricity

So na is just the normal Czech pattern in this kind of expression.

Yes, absolutely. That is also natural Czech.

There is a slight nuance:

• Druhé auto je na naftu. = The second car is diesel / is powered by diesel.
• Druhé auto jezdí na naftu. = The second car runs on diesel.

The version with je sounds a bit more like describing the car’s type or fuel system. The version with jezdí emphasizes how it operates.

In many everyday situations, both are fine.

No, Czech word order is fairly flexible.

The neutral order here is:

• Druhé auto jezdí na naftu.

But you can change the order for emphasis:

• Na naftu jezdí druhé auto.
  Emphasis on diesel
• Jezdí na naftu druhé auto.
  Less neutral, more context-dependent

So the original sentence is the most straightforward, neutral version.

Yes. Czech jezdit is broader than English drive.

It can be used for:

• a person going by vehicle
• a person driving regularly
• a vehicle itself moving or operating

So with auto as the subject, jezdí is perfectly normal and often corresponds to English runs rather than literally drives.