Learn Hardcore Polish: Zarówno książka, jak i gazeta leżą na stole. - Both the book and the newspaper are on the table.

It’s a correlative pair meaning both … and. You put zarówno before the first item and jak i before the second: Zarówno książka, jak i gazeta… = both the book and the newspaper…. It emphasizes that both elements are equally included.

Is the comma after książka required? I’ve seen both with and without it.

Both Zarówno książka, jak i gazeta… and Zarówno książka jak i gazeta… are commonly used and accepted. The comma is frequent in print but not obligatory when you’re just joining two noun phrases. You must use a comma if you’re joining whole clauses.

Why is the verb plural leżą and not singular leży?

Because the subject is compound: książka i gazeta. Polish uses plural agreement with such subjects, so you need third-person plural leżą. With a single item it would be singular: Książka leży na stole.

Could I use są instead of leżą?

Yes: Książka i gazeta są na stole is correct and simply says they are on the table. Leżą adds posture: they’re lying (flat). Polish often uses posture verbs for inanimate objects:

Flat/lying: leżeć (book, newspaper)
Standing upright: stać (bottle: Butelka stoi na stole.)
Hanging: wisieć (picture: Obraz wisi na ścianie.)

What case is na stole, and why not na stół?

Na stole uses the locative case after na to express a static location. Use the accusative to express motion onto something:

Location: leżą na stole (they’re lying on the table)
Motion: kładę je na stół (I’m putting them onto the table)

Why is it stole and not stołu or stołem?

Because stół declines, and the locative singular is stole. Other common forms you’ll see:

Nominative: stół (the table)
Genitive: stołu (of the table)
Accusative: stół (onto the table, after motion)
Instrumental: stołem (with the table)
Locative: stole (on/at the table, after certain prepositions like na, w, przy)

What case are książka and gazeta here? How would they look as objects?

They’re nominative singular (subjects): książka, gazeta. As direct objects (accusative) they’d be książkę, gazetę:

Widzę zarówno książkę, jak i gazetę. (I see both the book and the newspaper.)

Can I drop zarówno … jak i and just say Książka i gazeta leżą na stole?

Yes. Książka i gazeta leżą na stole is perfectly fine. Zarówno … jak i adds emphasis that both are included, a bit like stressing both in English.

Can I move parts around? What alternative word orders are natural?

Polish word order is flexible. These are natural:

Na stole leżą zarówno książka, jak i gazeta.
Leżą na stole zarówno książka, jak i gazeta. You can also coordinate other elements:
Zarówno na stole, jak i na półce leżą książki. Keep zarówno close to the element it pairs with jak i to avoid ambiguity.

How do I pronounce tricky bits like książka, leżą, stole, zarówno?

książka: roughly kshon-shka (the ą is a nasal o, like French on)
leżą: LE-zhon (ż = zh, ą nasal)
stole: STO-leh (short clear vowels)
zarówno: za-ROOV-no (ó = u) Polish stress is usually on the second-to-last syllable.

Are there alternatives to zarówno … jak i?

Yes; similar meanings with slight stylistic nuances:

tak … jak i: Tak książka, jak i gazeta leżą na stole.
jak również / a także: Książka, jak również gazeta, leżą na stole.
oraz / i: simpler and neutral: Książka oraz gazeta leżą na stole. You’ll also see zarówno … jak (without i); jak i is a bit more formal/symmetrical.

How do I say the negative (neither the book nor the newspaper is on the table)?

Use ani … ani plus the negative verb:

Ani książka, ani gazeta nie leżą na stole. Polish requires the double negative in such sentences.

If I replace the nouns with a pronoun, which one is correct?

Use one (non-masculine-personal plural) because the items are inanimate/feminine:

One leżą na stole. In the past tense: One leżały, not leżeli (the latter is for masculine-personal groups).

How do I say either the book or the newspaper is on the table?

Albo książka, albo gazeta jest na stole. (singular verb, because it’s one or the other) You can also use lub: Książka lub gazeta jest na stole.