Na obiedzie kładę serwetkę obok talerza, a mama poprawia obrus na stole.

In Polish, meals are often expressed with na + locative, especially when you mean at / during a meal.

So:

• na obiedzie = at dinner / during lunch
• na śniadaniu = at breakfast
• na kolacji = at supper / dinner

Using w obiedzie would usually sound wrong here, because w means in, and a meal is not treated as a container in this context.

In this sentence, Na obiedzie means something like At lunch / During the meal.

Obiedzie is the locative singular form of obiad.

The preposition na can take different cases depending on meaning. Here it means at / during, so it requires the locative:

• nominative: obiad
• locative: na obiedzie

This is why the noun changes form.

Because serwetkę is the direct object of the verb kłaść (to put / to place), so it must be in the accusative case.

• nominative: serwetka = napkin
• accusative: serwetkę

The sentence is describing what is being placed, so Polish uses the accusative:

• kładę serwetkę = I put the napkin

This is very common with action verbs:

• czytam książkę = I’m reading a book
• mam kawę = I have coffee
• widzę mamę = I see mom

Because obok requires the genitive case.

So:

• nominative: talerz = plate
• genitive: talerza
• obok talerza = next to the plate

Many Polish prepositions require specific cases, and obok is one of the ones that takes genitive.

Other examples:

• obok domu = next to the house
• obok krzesła = next to the chair

This is an aspect difference.

• kłaść = imperfective: focuses on the action, process, habit, or repeated activity
• położyć = perfective: focuses on completing the action once

In this sentence, kładę is imperfective, which fits well if you are describing what is happening in a general scene or routine.

Compare:

• Kładę serwetkę obok talerza. = I’m putting / I put the napkin next to the plate.
• Położę serwetkę obok talerza. = I will put the napkin next to the plate.
• Położyłam serwetkę obok talerza. = I put / have placed the napkin.

So kładę is natural for describing the situation as it unfolds.

Here poprawia means something like:

• straightens
• adjusts
• fixes
• smooths out

So mama poprawia obrus na stole suggests that mom is arranging the tablecloth so it sits properly on the table.

The verb poprawiać can have several related meanings depending on context:

• adjust something
• correct something
• improve something
• touch up something

In this sentence, it is clearly the physical meaning: she straightens/adjusts the tablecloth.

Na stole means on the table.

The preposition na here expresses location, so it takes the locative case:

• nominative: stół
• locative: na stole

So:

• obrus na stole = the tablecloth on the table

You could think of it as specifying where the tablecloth is being adjusted.

Both a and i can mean and, but they are not always used the same way.

• i simply adds one thing to another: and
• a often links two parallel or contrasting actions, something like and, while, or whereas

In this sentence:

• Na obiedzie kładę serwetkę obok talerza, a mama poprawia obrus na stole.

This feels like:

• I put the napkin next to the plate, and meanwhile mom adjusts the tablecloth on the table.

So a works well because it connects two related but separate actions by two different people.

No, Polish word order is fairly flexible, though some orders sound more natural than others depending on emphasis.

The original sentence is neutral and natural:

• Na obiedzie kładę serwetkę obok talerza, a mama poprawia obrus na stole.

But other versions are possible, for example:

• Kładę serwetkę obok talerza na obiedzie, a mama poprawia obrus na stole.
• Mama poprawia obrus na stole, a ja kładę serwetkę obok talerza.

However, changing the order changes the emphasis or can make the sentence sound less smooth. Polish often puts important new information later, but context matters a lot.

So the sentence is not fixed word-for-word, but the original order is a very natural one.

Polish often omits subject pronouns when the verb already shows who is doing the action.

• kładę already means I put / I am putting
• so you do not need ja

But with mama poprawia, the noun mama is used because the speaker wants to say explicitly who performs the second action.

So the structure is:

• [I] put the napkin...
• and mom adjusts the tablecloth...

If you added ja, it would usually create emphasis:

• Ja kładę serwetkę..., a mama poprawia obrus... = I’m the one putting the napkin..., and mom is adjusting the tablecloth...

Yes, in this context:

• serwetka = napkin
• obrus = tablecloth

A small note:

• serwetka can sometimes mean a decorative cloth or serviette in some contexts, but at the table it usually means napkin
• obrus is specifically the cloth covering the table

So these are the most natural meanings here.

A very natural English rendering would be:

• At lunch, I put the napkin next to the plate, and Mom straightens the tablecloth on the table.

Or, if you want it to sound more natural in everyday English:

• At lunch, I place the napkin next to the plate, and Mom straightens the tablecloth.
• During lunch, I put the napkin beside the plate, and Mom adjusts the tablecloth on the table.

English may omit on the table if it feels obvious, but Polish often keeps such location phrases more explicitly.