Ten płyn pachnie ładnie, ale proszek do prania stoi w łazience.

Because płyn is a masculine singular noun, and ten has to agree with it in gender and number.

• ten = masculine singular
• ta = feminine singular
• to = neuter singular

So:

• ten płyn = correct
• ta płyn = incorrect
• to płyn = incorrect

This kind of agreement is very important in Polish.

Literally, ten is a demonstrative pronoun, so it most directly means this.

So ten płyn is most literally this liquid / this detergent.

However, when English translates a sentence naturally, ten can sometimes feel a bit like the if the object is already known from context. Polish does not have articles like a and the, so learners sometimes notice that ten seems to “add specificity.”

Still, grammatically, ten is not an article. It is a word meaning this.

Płyn literally means liquid. In everyday usage, though, it can also mean a liquid cleaning product or liquid detergent, depending on context.

So in this sentence, ten płyn probably means something like:

• this liquid detergent
• this cleaning liquid
• or simply this liquid

Polish often relies on context more than English does.

Pachnie comes from pachnieć, which means to smell.

In Polish, pachnieć usually has a neutral or positive feel, often closer to to smell nice or to have a smell.

Examples:

• To pachnie kawą. = It smells like coffee.
• Kwiaty pięknie pachną. = The flowers smell beautiful / smell lovely.

If something smells bad, Polish more often uses śmierdzieć:

• To śmierdzi. = It stinks.

So pachnie ładnie sounds natural because it reinforces that the smell is pleasant.

Because ładnie is an adverb, and it modifies the verb pachnie.

• ładny = adjective = pretty / nice
• ładnie = adverb = nicely

In this sentence, you are describing how it smells, not describing the noun płyn directly.

So:

• ładny płyn = a nice-looking liquid / a nice liquid
• płyn pachnie ładnie = the liquid smells nice

This adjective/adverb distinction is very common in Polish.

Because Polish often builds compound meanings with a noun + do + another noun.

Here:

• proszek = powder
• do = for
• prania = washing / laundry

So proszek do prania literally means powder for washing, which is the normal way to say washing powder or laundry detergent.

This pattern is very common:

• szczoteczka do zębów = toothbrush
• maszyna do pisania = typewriter
• buty do biegania = running shoes

Because the preposition do requires the genitive case.

The base form is:

• pranie = washing / laundry

After do, it changes to:

• do prania

So:

• proszek do prania = powder for washing
• środek do czyszczenia = cleaning agent
• woda do picia = drinking water

This is a very useful pattern: do + genitive often expresses purpose.

This is a very common Polish way of speaking.

Polish often uses verbs like:

• stać = to stand
• leżeć = to lie
• wisieć = to hang

even for ordinary objects, where English would often simply say is.

So proszek do prania stoi w łazience means something like:

• the washing powder is standing in the bathroom
• but in natural English: the washing powder is in the bathroom

Polish tends to describe the object’s physical position more specifically than English.

Because w can take different cases depending on meaning.

Here it means in with a static location, so it takes the locative case:

• łazienka = bathroom
• w łazience = in the bathroom

If there were movement into the bathroom, Polish would use the accusative:

• wchodzę w łazienkę is not standard for this meaning
• normally Polish says wchodzę do łazienki = I’m going into the bathroom

So in this sentence:

• stoi w łazience = it is located in the bathroom

Because in Polish, ale normally introduces a new clause, and it is preceded by a comma.

• ..., ale ... = ..., but ...

So the comma here is standard punctuation.

This is similar to many Polish conjunctions that connect clauses. In careful writing, punctuation is more consistently marked than in English.

Yes, Polish word order is fairly flexible, because the endings carry a lot of the grammar.

The original sentence is neutral and natural:

• Ten płyn pachnie ładnie, ale proszek do prania stoi w łazience.

But you could also hear:

• Ten płyn ładnie pachnie, ale proszek do prania stoi w łazience.
• Ale proszek do prania stoi w łazience.
• W łazience stoi proszek do prania.

The meaning stays similar, but the emphasis changes.

For example:

• W łazience stoi proszek do prania puts more focus on where it is.
• Ten płyn ładnie pachnie sounds slightly more natural to some speakers than pachnie ładnie, but both are acceptable.

So the given word order is correct, but not the only possibility.