Trzeba nie tyle wyrzucić butelkę, co ją opróżnić i oddzielić nakrętkę.

Trzeba is an impersonal word meaning something like it is necessary, one should, or you need to.

Polish often uses impersonal structures where English would use a subject:

• Trzeba iść. = You have to go / One must go.
• Trzeba to zrobić. = This needs to be done / You need to do this.

So in Trzeba nie tyle wyrzucić butelkę, co ją opróżnić i oddzielić nakrętkę, the idea is general: it is not addressed to one specific person, but to people in general.

This is a very common Polish structure. Nie tyle ..., co ... means:

• not so much ... as ...
• less ... than ...
• rather than ...

So:

• nie tyle wyrzucić butelkę, co ją opróżnić i oddzielić nakrętkę

means:

• not so much to throw the bottle away as to empty it and separate the cap

It does not mean the first action is completely wrong. It means the speaker wants to shift the focus: the important thing is not merely throwing the bottle away, but preparing it properly first.

Examples:

• To nie tyle problem pieniędzy, co czasu.
  = It’s not so much a problem of money as of time.
• Nie tyle odpoczywał, co marnował czas.
  = He wasn’t so much resting as wasting time.

Because trzeba is normally followed by an infinitive.

Pattern:

• trzeba + infinitive

Examples:

• Trzeba poczekać. = You need to wait.
• Trzeba posprzątać. = It’s necessary to clean up.

So here:

• trzeba wyrzucić
• trzeba opróżnić
• trzeba oddzielić

All of them stay in the infinitive because they depend on trzeba.

Because these nouns are direct objects, so they are in the accusative case.

Base forms:

• butelka = bottle
• nakrętka = cap / screw cap

Accusative singular:

• butelkę
• nakrętkę

They are the things affected by the actions:

• wyrzucić butelkę = throw away the bottle
• oddzielić nakrętkę = separate the cap

This is very typical for feminine nouns ending in -a:

• nominative: książka
• accusative: książkę

So:

• butelka → butelkę
• nakrętka → nakrętkę

Ją refers to butelkę.

So:

• wyrzucić butelkę = throw away the bottle
• ją opróżnić = empty it

Here ją is the accusative singular pronoun meaning her/it, and for a noun like butelka it is translated as it.

So the sentence literally works like this:

• Trzeba nie tyle wyrzucić butelkę, co ją opróżnić...
• One should not so much throw away the bottle as empty it...

Both are grammatically possible, but ją opróżnić sounds more natural here.

In Polish, short unstressed pronouns such as go, ją, ci, mi, mu often come before the infinitive or verb phrase they belong to, especially in neutral speech:

• trzeba ją opróżnić
• muszę go zobaczyć
• chcę ci pomóc

You can also place the pronoun after the infinitive in some contexts, but it often sounds more emphatic, marked, or less natural depending on the sentence.

So co ją opróżnić is the smoother, more standard choice here.

They are perfective because the sentence is about completing specific actions.

• wyrzucić = to throw away completely
• opróżnić = to empty completely
• oddzielić = to separate

Their imperfective partners would be:

• wyrzucać
• opróżniać
• oddzielać

With trzeba, both aspects are possible, but they mean slightly different things:

• Trzeba opróżnić butelkę.
  = The bottle needs to be emptied (focus on completing the action)
• Trzeba opróżniać butelki przed wyrzuceniem.
  = Bottles need to be emptied before throwing them away (habit/rule/process)

In your sentence, the speaker means concrete, completed preparation steps, so perfective verbs are the natural choice.

No. Here co does not mean what.

In the structure nie tyle ..., co ..., co acts like a conjunction meaning something close to:

• as
• but rather
• than
• instead

So in this sentence it is part of a fixed comparison/correction pattern:

• nie tyle X, co Y

You should learn it as one whole expression rather than trying to interpret co separately as what.

Because Polish often omits information that is obvious from context.

If you are talking about a bottle and its cap, then oddzielić nakrętkę naturally means separate the cap from the bottle.

A fuller version would be:

• oddzielić nakrętkę od butelki

That is also correct, but less economical. Since butelka was already mentioned, the shorter version sounds perfectly natural.

In real life, you might also hear:

• odkręcić nakrętkę = unscrew the cap
• zdjąć nakrętkę = take the cap off
• oddzielić nakrętkę od butelki = separate the cap from the bottle

Oddzielić fits well in recycling instructions, because the point is separation of materials/parts.

Yes. Wyrzucić is a very common verb meaning throw away, throw out, or more generally discard.

Depending on context:

• wyrzucić butelkę = throw away the bottle
• wyrzucić śmieci = take out / throw away the rubbish
• wyrzucić stare ubrania = throw out old clothes

In a recycling context, English may prefer dispose of or put in the bin/container, but the Polish verb itself is the ordinary everyday word wyrzucić.

It sounds like a general instruction or recommendation, especially the kind you might see in recycling guidance.

Because it uses trzeba, it is less direct than an imperative:

• Opróżnij butelkę i oddziel nakrętkę.
  = Empty the bottle and separate the cap.
  Direct command.

• Trzeba opróżnić butelkę i oddzielić nakrętkę.
  = You should empty the bottle and separate the cap.
  General instruction / rule.

So the tone is impersonal and instructional rather than personally commanding.

Yes. A simpler version might be:

• Nie wystarczy wyrzucić butelki — trzeba ją opróżnić i oddzielić nakrętkę.
• Zamiast po prostu wyrzucić butelkę, trzeba ją opróżnić i oddzielić nakrętkę.

These versions are easier to understand for learners, but nie tyle ..., co ... is more elegant and compact.

So the original sentence is a bit more advanced stylistically, but still perfectly natural.