Diagnosta skontrolował oświetlenie.

• Diagnosta = a noun: the person doing the action
• skontrolował = a verb: the completed action in the past
• oświetlenie = a noun: the thing being inspected

So the sentence structure is:

subject + verb + object

That is very similar to basic English word order.

The ending -ł is a typical marker of the past tense in Polish for a masculine singular subject.

Here, diagnosta refers to one male person, so the verb is:

• skontrolował = he inspected / he checked

Compare:

• skontrolował = he inspected
• skontrolowała = she inspected
• skontrolowali = they inspected (masculine-personal group)
• skontrolowały = they inspected (non-masculine-personal group)

So the verb agrees with the subject in gender and number in the past tense.

Diagnosta is simply the standard Polish noun for a diagnostician / inspector / diagnostic specialist, depending on context.

A useful thing to notice is that although diagnosta ends in -a, it is usually a masculine noun when referring to a man. Polish has a small group of masculine nouns with -a endings, often referring to professions or people, for example:

• mężczyzna = man
• kolega = male friend/colleague
• poeta = poet
• diagnosta = diagnostician/inspector

So even though the ending may look feminine to an English learner, the grammar here is masculine, which is why the verb is skontrolował.

Oświetlenie is in the accusative case here because it is the direct object of the verb skontrolować.

However, oświetlenie is a neuter noun, and for many neuter nouns the nominative and accusative forms are identical.

So:

• nominative: oświetlenie
• accusative: oświetlenie

That is why the word looks unchanged even though it is functioning as the object.

The verb skontrolować normally takes the accusative for the thing being checked or inspected.

So:

• skontrolować dokumenty = to inspect/check the documents
• skontrolować samochód = to inspect/check the car
• skontrolować oświetlenie = to inspect/check the lighting

This is similar to English inspect/check something.

This is a question of aspect, which is very important in Polish.

• skontrolować = perfective
• kontrolować = imperfective

In this sentence, skontrolował comes from skontrolować, so it means the inspection was viewed as completed.

Very roughly:

• kontrolował oświetlenie = he was inspecting / he inspected (focus on the process, repeated action, or no emphasis on completion)
• skontrolował oświetlenie = he inspected the lighting and completed that inspection

English often does not mark this distinction as clearly as Polish does, so this is something learners need to get used to.

Yes. In many contexts, skontrolować can be translated as inspect, check, or examine, depending on the situation.

The exact English choice depends on context:

• technical or official context: inspect
• more general context: check

With diagnosta, a technical or official meaning is often likely, so inspected is often a good translation.

Yes, it is very natural.

The basic neutral Polish word order here is:

Diagnosta (subject) + skontrolował (verb) + oświetlenie (object)

Polish word order is more flexible than English because cases show grammatical roles, but the sentence as given is the most straightforward, neutral version.

You could change the order for emphasis, for example:

• Oświetlenie skontrolował diagnosta = It was the lighting that the inspector checked / The inspector checked the lighting

But the original sentence is the plain, standard order.

A rough pronunciation guide is:

o-shfyeht-LEH-nye

A few key sounds:

• ś = a soft sh-like sound
• w in Polish sounds like English v, but here in ośw- it combines with the previous consonant and may sound close to shf / shv
• ł sounds like English w
• nie at the end is usually like nye

If you want to break it up:

• o-świet-le-nie

The stress is on the penultimate syllable:

• o-świet-LE-nie

Polish has no articles, so there is no direct equivalent of a/an/the.

That means:

• Diagnosta skontrolował oświetlenie could mean
  • The inspector inspected the lighting
  • An inspector inspected the lighting

Which one is intended depends on context.

This is normal in Polish, and learners have to get used to understanding definiteness from the situation rather than from an article.

The main change would be the past-tense verb ending.

If the subject is a woman, you would say:

• Diagnostka skontrolowała oświetlenie.

Here:

• diagnostka = female diagnostician/inspector
• skontrolowała = she inspected

The object oświetlenie stays the same.

Oświetlenie usually means lighting or illumination, especially as a system or set of lights.

Depending on context, it could refer to:

• the lighting in a room
• a vehicle's lights
• technical illumination

So in a practical inspection context, it often means the lighting system or the lights rather than just abstract light.

Not with the same aspect and meaning.

Because skontrolować is perfective, its present-tense forms usually refer to the future, not an ongoing present action.

For example:

• skontroluje = he will inspect

If you want a real present tense meaning like is checking / checks, you normally use the imperfective verb:

• Diagnosta kontroluje oświetlenie. = The inspector is checking / checks the lighting.

So:

• kontroluje = present, ongoing/habitual
• skontrolował = past, completed
• skontroluje = future, completed