Learn Hardcore Polish: Ona przygotuje różne pomysły, a ja wybiorę jeden. - She will prepare various ideas, and I will choose one.

Yes, you can drop them. Polish is a pro‑drop language, so subjects are often omitted. They’re used here for clarity and contrast: “she” will do one thing, “I” will do another. All of these are grammatical, depending on context:

Ona przygotuje różne pomysły, a ja wybiorę jeden.
Ona przygotuje różne pomysły, a wybiorę jeden.
Przygotuje różne pomysły, a ja wybiorę jeden. Without context, “przygotuje” alone doesn’t tell you who (he/she/it), so “ona” can prevent ambiguity.

Why use “a” here instead of “i” or “ale”? And why is there a comma before “a”?

“a” means “and/whereas” and often contrasts two different subjects or roles, which fits well here (she vs I).
“i” is a plain “and.” “Ona przygotuje…, i ja wybiorę…” is possible but sounds clunky; if you use “i,” you’d usually drop “ja”: “Ona przygotuje różne pomysły i wybiorę jeden.” Still, “a” is more natural because it highlights the division of labor.
“ale” is “but,” a stronger adversative; there’s no opposition here, so it’s not ideal. Comma: Polish normally puts a comma before “a” when it links clauses. With “i,” you typically don’t use a comma.

What tense/aspect are “przygotuje” and “wybiorę”?

They’re simple future forms of perfective verbs:

przygotuje = 3rd person singular future of the perfective “przygotować”
wybiorę = 1st person singular future of the perfective “wybrać” Perfective aspect presents single, completed events; perfective “present” forms refer to the future.

Could I use the compound future with imperfective verbs instead? How would that change the meaning?

Yes. Imperfective compound future emphasizes ongoing/repeated action:

Ona będzie przygotowywać różne pomysły… (she will be preparing/working on ideas)
…a ja będę wybierać (m: wybierał, f: wybierała) jeden. That last part suggests a process or repeated choosing, so more natural is to keep perfective for a one‑off choice: “…a ja wybiorę jeden.” Mixing “będzie przygotowywać” (process) with “wybiorę” (one completion) is very common and natural.

Is “przygotować pomysły” idiomatic? Would another verb be better?

It’s fine if she’s preparing a set of ideas to present (e.g., for a meeting). If you mean “come up with” ideas, use:

wymyśli różne pomysły (she will think up ideas) If you mean “develop/refine”:
opracuje różne pomysły If you mean “present/propose”:
przedstawi / zaproponuje różne pomysły Choose the verb that matches your intent.

What case are “różne pomysły” in, and why is it “różne,” not “różnych”?

It’s accusative plural, the direct object of “przygotuje.” For masculine inanimate nouns like “pomysł,” the accusative plural looks like the nominative plural: “pomysły.” The adjective agrees and uses the non‑masculine‑personal plural: “różne.” “Różnych” is genitive/locative/instrumental plural and would appear after certain quantifiers or prepositions, e.g.:

Przygotuje kilka różnych pomysłów.
Nie ma różnych pomysłów (genitive after negation).

Why is it “jeden,” not “jednego,” after “wybiorę”?

Because the implied noun “pomysł” is masculine inanimate, and in the singular accusative, masculine inanimate equals the nominative: “jeden.” You use “jednego” in the accusative only for masculine animate nouns:

Wybiorę jednego chłopca (one boy). With “pomysł,” you can also say it explicitly: “Wybiorę jeden pomysł.”

What if the noun were feminine or neuter—how does “one” change?

Feminine: “jedna” (nominative), “jedną” (accusative). Example: Wybiorę jedną (książkę).
Neuter: “jedno” (both nominative and accusative). Example: Wybiorę jedno (zadanie). When you omit the noun, the form of “jeden/jedna/jedno” must still match the implied noun’s gender and case.

Do I need to add “z nich” to say “one of them”?

Not necessarily. In context, “wybiorę jeden” usually implies “one of those [ideas].” Add it if you want to be explicit or emphatic:

…a ja wybiorę jeden z nich. You can also say:
…a ja wybiorę jeden z przygotowanych (one of the prepared ones).

Is the word order fixed, or can I rearrange it for emphasis?

Polish word order is flexible. You can move constituents for emphasis:

Ja wybiorę jeden, a ona przygotuje różne pomysły. (contrast: I vs she)
Różne pomysły przygotuje ona, a jeden wybiorę ja. (strong emphasis on who does what)
Ona przygotuje różne pomysły, a jeden wybiorę. (elliptical; the object “jeden” is fronted) All are grammatical; choose based on what you want to highlight.

How should I pronounce the tricky letters here?

ó = “oo” (like “food”): in różne.
ż and rz = “zh” (like the s in “measure”): różne (ż), przy‑ (rz in “przy”).
ł = English “w.”
w = English “v.”
j = English “y.”
ę at word end often sounds like a plain “e” with light nasalization: “wybiorę” ≈ “vy-BYOR-eh.” Approximate whole sentence: “Ona pshi-go-TOO-ye ROO-zh-neh, a ya vi-BYOR-eh YEH-den.”

Why isn’t it “różni pomysły”?

“Różni” is the masculine personal plural form (used for groups of people). “Pomysły” are inanimate, so you need the non‑masculine‑personal plural “różne.”

Does the verb show gender here?

No. In the present and in the simple future of perfective verbs, Polish verbs don’t show gender. Gender shows up in the past tense and conditional (e.g., “wybrałem/wybrałam”). That’s another reason speakers may add “ona” to clarify who the subject is.