Learn Hardcore Polish: Na lekcji online czasem nie działa kamera albo mikrofon. - In an online class sometimes the camera or the microphone doesn’t work.

You could say w lekcji, but that sounds more like “inside the lesson” in a very literal or technical sense (e.g. “in this exercise/lesson in a textbook”). For the normal meaning “in class”, na lekcji is the standard, natural phrase.

What case is lekcji, and why isn’t it lekcja?

Lekcji is in the locative case, singular.

The basic (dictionary) form is lekcja (nominative singular).
After the preposition na in the meaning “in/at (a place/event)”, Polish uses the locative case.
Feminine nouns like lekcja often form the locative singular with the ending -i or -y:
- lekcja → lekcji
- szkoła → szkole
- kawa → kawie

So:

lekcja – a lesson (subject form, nominative)
na lekcji – in the lesson / in class (locative after na)

Why does online stay the same and not change its ending like lekcji?

Online is an English loanword used in Polish as an indeclinable adjective/adverb. That means:

It does not change form for case, number, or gender.
It simply stays online in all contexts.

So you get:

lekcja online – an online lesson
na lekcji online – in an online lesson
spotkanie online – an online meeting
rozmowa online – an online conversation

Native Polish adjectives would change according to gender and case, e.g.:

lekcja zdalna → na lekcji zdalnej

But online just stays online.

Is online acting like an adjective (“online lesson”) or like an adverb here?

Functionally, it’s adjectival here: lekcja online means “online lesson”, so online is describing the type of lesson.

Polish treats many borrowed words flexibly, and grammarians may classify online slightly differently (adverbial vs adjectival use), but from a learner’s perspective:

When it comes after a noun like this (lekcja online), it behaves like an adjective: “(the) online lesson”.
It doesn’t take endings, unlike native adjectives, but it still modifies the noun.

So you can think of lekcja online exactly as “online lesson” in English.

Why is it działa and not something like pracuje or funkcjonuje?

In Polish, działać is the most common verb to say that a device works / is functioning.

kamera działa – the camera works
mikrofon nie działa – the microphone doesn’t work
komputer działa – the computer is working (functions)

Pracować literally means “to work” (as a person, or machinery in some contexts), but for devices, działać is much more idiomatic when you mean “it functions properly”.

You can also say funkcjonować, but that sounds a bit more formal or technical. In everyday speech, (nie) działa is the default way to talk about whether equipment is working.

Why is the verb singular (nie działa) when there are two things, kamera albo mikrofon?

The verb is singular because of how albo (“or”) works:

The idea is that only one of them is the problematic subject at any given time:
“Sometimes the camera or the microphone doesn’t work (one or the other).”

In both English and Polish, with “X or Y” you can use a singular verb if you are thinking of one item:

English: “The camera or the microphone doesn’t work.”
Polish: Kamera albo mikrofon nie działa.

You can also hear nie działają (plural), especially if the speaker thinks about them more as a set of possible devices, but:

nie działa kamera albo mikrofon – more natural for “one of them doesn’t work (at that time)”
nie działają kamera albo mikrofon – sounds more like “cameras or microphones (in general) tend not to work”, less natural in this sentence.

In your sentence, the singular nie działa fits the idea of “one or the other” malfunctioning.

What is the difference between albo, lub, and ani?

These all translate to some kind of “or”, but they’re used differently:

albo – “or” (often exclusive)
- kamera albo mikrofon – the camera or the microphone (usually one, not both)
- More everyday, a bit stronger, sometimes like “either … or …”.
lub – “or” (often inclusive)
- kamera lub mikrofon – the camera or the microphone (possibly both)
- More neutral, often used in written/formal language.
ani – “nor / or … not”
- Used with negation (usually with nie or żaden).
- Nie działa ani kamera, ani mikrofon. – Neither the camera nor the microphone works.
- Nie mam ani czasu, ani ochoty. – I have neither time nor desire.

In your sentence, albo is natural because it suggests one or the other device sometimes fails.

Why is nie written separately from działa, and when is nie written together with words?

With finite verbs, nie is normally written separately:

nie działa – doesn’t work
nie widzę – I don’t see
nie mam – I don’t have

You write nie together mainly with:

Most adjectives and adverbs:
- miły → niemiły – nice → unpleasant
- ciekawy → nieciekawy – interesting → uninteresting
- szybko → nieszybko – not quickly / slowly (in some contexts)
Many nouns:
- porządek → nieporządek – order → mess
- szczęście → nieszczęście – happiness → misfortune

So:

nie działa is verb + negation → two words.
niedziałający (“non-functioning”) is a participle used like an adjective → one word.

If the verb is negated (nie działa), why are kamera and mikrofon still in the nominative, not in the genitive?

The rule “negation → genitive” applies mainly to direct objects of transitive verbs, not to subjects.

Here:

kamera and mikrofon are the subjects of the sentence:
- (What doesn’t work?) → the camera or the microphone.
Subjects in Polish use the nominative case, even with negation:
- Kamera nie działa. – The camera doesn’t work.
- Mikrofon nie działa. – The microphone doesn’t work.

You get genitive under negation when you have a direct object:

Widzę kamerę. – I see the camera. (accusative)
Nie widzę kamery. – I don’t see the camera. (genitive after negation)

In your sentence, there is no direct object, just a subject and an intransitive verb, so nominative is correct.

Can the word order be changed? For example, can I say Kamera albo mikrofon czasem nie działa na lekcji online?

Yes, Polish word order is very flexible, and your alternative is correct. Some common variants:

Na lekcji online czasem nie działa kamera albo mikrofon.
– Sets the scene first (“In an online lesson…”).
Kamera albo mikrofon czasem nie działa na lekcji online.
– Puts more focus on which devices misbehave.
Czasem na lekcji online nie działa kamera albo mikrofon.
– Emphasizes “sometimes” right at the start.

All have the same basic meaning. Differences are more about focus/emphasis than grammar. For a learner, the original word order is a good, neutral model.

What is the difference between czasem and czasami?

Both czasem and czasami mean “sometimes”, and they are very close in meaning.

czasem – slightly shorter, very common in spoken language.
czasami – also very common; for some speakers it feels just a bit more neutral or slightly more formal, but the difference is tiny.

In your sentence, you could say:

Na lekcji online czasem nie działa kamera albo mikrofon.
Na lekcji online czasami nie działa kamera albo mikrofon.

Both are fully natural. For most purposes, you can treat them as interchangeable.

Where can I put czasem in the sentence? Does the position change the meaning?

You can move czasem around quite freely. These are all grammatical:

Na lekcji online czasem nie działa kamera albo mikrofon.
Na lekcji online nie działa czasem kamera albo mikrofon.
Czasem na lekcji online nie działa kamera albo mikrofon.

The basic meaning (“sometimes the camera or the microphone doesn’t work in an online class”) stays the same.

Subtle differences:

At the very beginning (Czasem…) – you stress the frequency first.
Right before the verb (czasem nie działa) – you naturally hear “sometimes doesn’t work” as a unit.
After nie działa – can sound like “doesn’t work, sometimes” with a tiny pause, but still normal.

For learners, putting czasem before the verb is a good default pattern.

Could I use podczas lekcji online instead of na lekcji online?

Yes, you can say:

Podczas lekcji online czasem nie działa kamera albo mikrofon.

This is grammatically fine and means the same thing. The nuance:

na lekcji online – very natural, everyday, typical way to say “in an online class”.
podczas lekcji online – slightly more formal/literary, explicitly means “during the online lesson”.

So both are correct, but in casual speech about online classes, na lekcji online is probably more common.

Why is the verb działa (imperfective) and not a perfective form like zadziała?

The verb działać is imperfective, which is used for:

repeated / habitual actions
ongoing states

Here we’re talking about what sometimes happens in general during online lessons, so imperfective is exactly what you want:

czasem nie działa – sometimes it doesn’t work (repeated situation)

A perfective form like zadziałać (“to work once / to start working successfully”) would sound like a single event:

Kamera w końcu zadziałała. – The camera finally worked (this one time).

In your general, habitual statement, imperfective działa is the only natural choice.