Learn Hardcore Polish: Po kilku latach ona zrobiła podobną zmianę w swojej karierze. - After a few years she made a similar change in her career.

kilku – genitive plural of kilka (“a few/several”); after po
- time expression, you use po
  - locative, but numerals like kilka normally govern genitive, hence kilku.
latach – locative plural of lata (“years”).

So the structure is:

po
- kilku (genitive, required by the numeral) + latach (locative, required by po)

Using po kilka lat would be ungrammatical in this meaning and case frame.

What exactly does “po” mean here? Can it also mean “for several years”?

In this sentence, po means “after” in a temporal sense:

Po kilku latach = After a few years

It does not mean “for” here. To express “for several years” in Polish, you would typically use:

przez kilka lat – “for several years”
od kilku lat – “for several years now / for the last few years” (ongoing up to now)

So:

po kilku latach → after a few years (had passed)
przez kilka lat → for a few years (duration)
od kilku lat → for a few years (up to now)

Why is “latach” used instead of just “lat”?

Because of case.

lat is genitive plural (often used for “x years” as a standalone phrase, e.g. kilka lat, pięć lat).
latach is locative plural.

The preposition po with a time expression meaning “after” requires locative, so:

“after a few years” → po kilku latach (locative).
if you just say “a few years” (without po), you’d use kilka lat (genitive).

So latach is there purely because of the preposition’s grammar.

Is it necessary to have “ona” in the sentence? Could I say just “Po kilku latach zrobiła podobną zmianę w swojej karierze”?

You can absolutely omit ona, and in natural Polish you very often would:

Po kilku latach zrobiła podobną zmianę w swojej karierze.

Polish is a pro‑drop language: the verb ending -ła already shows that the subject is she. You add ona if you want to:

emphasize the subject (contrast: not someone else, but her), or
introduce or re-introduce the subject clearly in context.

Without special emphasis, the version without “ona” sounds slightly more natural.

Is the word order fixed? Could I say “Ona po kilku latach zrobiła podobną zmianę w swojej karierze”?

Yes, that order is also correct:

Ona po kilku latach zrobiła podobną zmianę w swojej karierze.

Polish word order is relatively flexible; you usually adjust it for emphasis and rhythm. Nuances:

Po kilku latach ona zrobiła… – mild focus on the time (“after a few years, she (as opposed to someone else) made…”).
Ona po kilku latach zrobiła… – mild focus on her as the doer (“she, after a few years, made…”).
Po kilku latach zrobiła… – neutral, very natural in context.

All three are grammatically fine; context decides which sounds better.

Is “zrobiła zmianę” a natural phrase in Polish, or is it a calque from English “made a change”?

“zrobiła zmianę” is understandable and grammatically correct, but it is less idiomatic than other options. More natural choices would be:

dokonała podobnej zmiany w swojej karierze – very natural and common
wprowadziła podobną zmianę w swojej karierze
zmieniła coś w swojej karierze / dokonała podobnej zmiany w karierze

Polish tends to use verbs like dokonać, wprowadzić, przeprowadzić or simply zmienić with zmiana, rather than zrobić zmianę. So if you want to sound especially natural, consider one of the alternatives above.

Why is it “podobną zmianę” and not something like “podobny zmiana”?

Because adjectives must agree with nouns in gender, number, and case.

zmiana – feminine, singular, accusative (here it’s a direct object).
The adjective podobny must therefore also be:
- feminine
- singular
- accusative

So it becomes podobną. Pattern:

Nom. sg. fem.: podobna zmiana
Acc. sg. fem.: podobną zmianę

Saying “podobny zmiana” would mix masculine form (podobny) with feminine noun (zmiana), which is incorrect.

Why is it “w swojej karierze” and not “w swoją karierę”?

Because of the preposition w and the meaning:

w
- locative → “in” (location/state)
  - w swojej karierze – in her career (within the sphere of her career)
w
- accusative → “into / to (inside)” (movement into)
  - w swoją karierę would suggest movement into her career, which doesn’t fit the intended meaning.

Here we’re talking about a change within an existing career, not moving into a career, so we use locative:

karierze – locative of kariera
w swojej karierze – “in her career”

What is the function of “swojej” here, and how is it different from “jej”?

“swojej” is the reflexive possessive pronoun (from swój). It means “one’s own” and is used when the possessor is the subject of the sentence.

Subject: ona
Possessed thing: kariera
Possessive: swojej → her own

You would normally choose:

swojej karierze if the career belongs to the subject (“her own career”).
jej karierze if the career belongs to another female mentioned in context, not the subject.

Example contrast:

Ona zrobiła zmianę w swojej karierze. – She changed her own career.
Ona zrobiła zmianę w jej karierze. – She changed another woman’s career.

So swój helps avoid ambiguity about whose career is meant.

Why is it “swojej karierze” and not something like “swoja kariera”?

Again, this is about case and agreement:

The preposition w with the meaning “in (something)” requires locative.
The noun:
- kariera → nominative singular
- karierze → locative singular (feminine)
The possessive adjective swój must match:
- gender: feminine
- number: singular
- case: locative

So you get:

w
- swojej karierze (locative) – correct

Forms like swoja kariera are nominative and would only be used if that phrase were the subject, e.g.:

To jest jej własna kariera. – This is her own career.

What is the difference between “zrobiła” and “robiła” here?

It’s the aspect of the verb:

zrobiła – past tense of zrobić (perfective)
- Focus on completed action: she did/made the change (once, done).
robiła – past tense of robić (imperfective)
- Focus on process/repetition/incompleteness: she was making / used to make changes.

In this sentence, we describe a single, finished change, so the perfective form zrobiła is appropriate. Using robiła here would sound like she was in the process of making a change or repeatedly making changes, which changes the meaning.

How do people actually pronounce “w swojej”? It seems hard to say.

In casual speech, Polish tends to simplify consonant clusters and link words smoothly.

For w swojej:

The w is often very weak or almost silent before s, so it may sound like “swojej” with just a slight labial movement.
The phrase tends to be pronounced as one unit: /fsˈvɔ.jɛj/ or close to /sˈvɔ.jɛj/ depending on speaker and speed.

So you’ll often hear something like:

Po kilku latach [w]swojej karierze…

Don’t be surprised if the w is barely audible; this is normal in fast, natural speech.

Can I replace “kilku” with “paru”? What’s the difference?

Yes, you can say:

Po paru latach ona zrobiła podobną zmianę w swojej karierze.

Differences:

kilku – neutral, slightly more standard.
paru – very common in informal or conversational speech; feels a bit more colloquial.

Meaning-wise, both are “a few / several”; there is no strong numerical difference. In written, more formal Polish, kilku is safer; in everyday speech, paru is extremely common.