На сковороде жарится картофель.

This is a very natural Russian way to set the scene first: On/In the frying pan, potatoes are frying.

Russian word order is much more flexible than English word order. Starting with На сковороде puts the location first and sounds perfectly normal.

A more direct English-like order is also possible:

Картофель жарится на сковороде.

Both mean the same thing, but the emphasis shifts a little:

• На сковороде жарится картофель = the speaker first points to the pan / location
• Картофель жарится на сковороде = the speaker first names what is frying

With сковорода (frying pan), Russian normally uses на, not в, when talking about cooking:

• жарить на сковороде = to fry in a pan
• готовить на сковороде = to cook in a pan

To an English speaker, in a pan feels more logical, but Russian idiom prefers на here.

So:

• на сковороде = the normal Russian expression
• в сковороде would sound unnatural in this context

Because after на meaning location, Russian usually uses the prepositional case.

The noun changes like this:

• сковорода = frying pan
• на сковороде = in/on the frying pan

This is a regular feminine noun pattern:

• комната → в комнате
• газета → в газете
• сковорода → на сковороде

So сковороде is simply the prepositional form of сковорода.

Жарится comes from жариться, the reflexive form of жарить.

Very roughly:

• жарить = to fry something
• жариться = to be frying / to fry itself / to be fried

In this sentence, жарится means:

• is frying
• is being fried

A natural English translation is usually The potatoes are frying in the pan.

Russian often uses this reflexive form when the process is happening and the person doing it is not important.

The ending -ся originally comes from a reflexive idea, but in real Russian it does several jobs.

Here it does not literally mean that the potato is frying itself on purpose. Instead, it gives a middle/passive-like meaning:

• Картофель жарит повар. = The cook is frying the potatoes.
• Картофель жарится. = The potatoes are frying / being fried.

So in this sentence, -ся helps express the cooking process without naming the cook.

This is very common in Russian:

• Дом строится. = The house is being built.
• Суп варится. = The soup is cooking / boiling.
• Картофель жарится. = The potatoes are frying.

In Russian, картофель is often treated as a mass noun when talking about potato as food, like potato or potatoes in a general sense.

So:

• картофель can mean potato as a foodstuff
• in context, it may translate naturally as potatoes

That is why the verb is also singular:

• Картофель жарится. = Potatoes are frying / The potato is frying

This is about meaning, not word-for-word matching.

In everyday speech, many people would more naturally say:

На сковороде жарится картошка.

That sounds more colloquial and common in everyday Russian.

Because in this sentence, картофель is in the nominative case, and the verb agrees with it:

• картофель = nominative singular
• жарится = 3rd person singular

So grammatically, картофель is the subject: it is the thing undergoing the process.

Compare:

• Я жарю картофель. = I am frying potatoes.
  Here картофель is the object.

• Картофель жарится. = Potatoes are frying / being fried.
  Here картофель is the subject.

Yes, but it means something a little different.

• На сковороде жарится картофель. = Potatoes are frying / being fried in the pan.
• На сковороде жарят картофель. = They are frying potatoes in the pan / Potatoes are fried in a pan.

The second version uses an indefinite personal construction:

• жарят = they fry, but usually with no specific they in mind

So:

• жарится focuses on the process happening to the food
• жарят implies some unnamed people are doing the frying

Жарится is:

• present tense
• imperfective aspect

The imperfective aspect shows the process as ongoing, repeated, or uncompleted.

So here it means:

• the frying is happening now
• we are looking at the process, not the result

That is why it matches English is frying well.

If you wanted to emphasize completion or result, Russian would usually choose a different verb or prefix, depending on nuance.

It is correct and natural, but картофель sounds a bit more neutral or slightly formal than everyday speech.

In ordinary conversation, many speakers would say:

На сковороде жарится картошка.

Both are correct:

• картофель = more standard, dictionary-style, a bit more formal/neutral
• картошка = everyday spoken word

So the given sentence is fine, but картошка would often sound more conversational.

The stress is:

На сковороде́ жа́рится карто́фель.

A rough pronunciation guide:

• На = na
• сковороде́ = skava-ra-DYE
• жа́рится = ZHA-ri-tsa
• карто́фель = kar-TO-fyel

The most important stresses to remember are:

• сковороде́
• жа́рится
• карто́фель

Russian has no articles like a or the.

So картофель can mean:

• potato
• the potato
• potatoes
• the potatoes

The exact meaning depends on context.

That is completely normal in Russian. The listener figures it out from the situation, word order, and the broader context.