Learn Hardcore Polish: Twoja dziewczyna zastanawia się, czy powiesz jej całą prawdę. - Your girlfriend is wondering whether you will tell her the whole truth.

“girl” (female person, usually young)
- Ta dziewczyna jest bardzo wysoka. – That girl is very tall.
“girlfriend” (romantic partner)
- To jest moja dziewczyna. – This is my girlfriend.

In your sentence Twoja dziewczyna zastanawia się..., context strongly suggests “your girlfriend”, not just “some girl you know”.

What is the role of się in zastanawia się?

zastanawia się is the reflexive form of the verb zastanawiać się, which means “to wonder / to think over / to ponder”.

zastanawiać (without się) would usually mean “to make someone think/consider” (less common in everyday speech).
zastanawiać się (with się) = “to be wondering”, “to be thinking about something”.

Polish often uses się to create reflexive verbs with meanings that in English are non‑reflexive, e.g.:

uczyć się – to learn
bać się – to be afraid
śmiać się – to laugh

So Twoja dziewczyna zastanawia się = “Your girlfriend is wondering / is thinking (to herself)”.

Why is there a comma before czy?

In Polish, a comma is used before most subordinate clauses, and clauses introduced by czy (in the meaning “whether / if”) count as subordinate clauses.

So:

Twoja dziewczyna zastanawia się, czy powiesz jej całą prawdę.

The main clause is:

Twoja dziewczyna zastanawia się – Your girlfriend is wondering

The subordinate clause (what she is wondering) is:

czy powiesz jej całą prawdę – whether you will tell her the whole truth

That boundary between the two clauses is marked with a comma.

What does czy do here, and how is it different from English “if / whether”?

Here czy introduces an indirect yes/no question:

czy powiesz jej całą prawdę – whether you will tell her the whole truth

In this use, czy is roughly equivalent to English “whether / if” (in indirect questions):

Zastanawia się, czy przyjdziesz. – She’s wondering if / whether you’ll come.

Important points:

czy is used for yes/no questions, not for wh‑ questions (who, what, where, etc.).
In direct questions, you can start with czy:
- Czy powiesz mi całą prawdę? – Will you tell me the whole truth?
In indirect questions, it works like English “if/whether”:
- Ona chce wiedzieć, czy powiesz jej prawdę. – She wants to know whether you will tell her the truth.

Don’t confuse this czy with czy meaning “or” (used mainly in questions, e.g. Kawa czy herbata? – Coffee or tea?).

Why is it powiesz and not something like będziesz mówić?

Both forms can refer to the future, but they differ in aspect and nuance:

powiesz – 2nd person singular, future, perfective of powiedzieć
- Focus on one complete act of saying/telling.
- “You will tell (once, fully, as a single action).”
będziesz mówić – 2nd person singular, future, imperfective of mówić
- Focus on the process, repeated, ongoing, or incomplete speaking.

In czy powiesz jej całą prawdę, they’re asking whether you will actually reveal the whole truth at some point, treated as a single decisive act. That’s why the perfective powiesz is natural here.

będziesz mówić jej całą prawdę would sound more like “you will be telling her the whole truth (on an ongoing basis)” and is much less natural in this specific context.

What exactly does jej mean here, and why not ją?

jej is a feminine pronoun form that can be genitive or dative. Here it’s dative, meaning “to her / for her” (indirect object).

powiedzieć coś komuś – to tell something to someone
- coś (something) is in the accusative
- komuś (to someone) is in the dative

In your sentence:

całą prawdę – the thing told (accusative)
jej – the person you tell it to (dative, “to her”)

Compare:

Widzę ją. – I see her. (ją is accusative, direct object)
Mówię jej prawdę. – I’m telling her the truth. (jej is dative: to her)

So:

powiesz jej całą prawdę = you will tell her the whole truth.

Why is it całą prawdę and not cała prawda?

That’s because of case and agreement.

prawda is a feminine noun.
- Nominative singular: prawda (dictionary form)
- Accusative singular: prawdę
cały / cała / całe is an adjective meaning “whole / entire / all (of)”, and it must agree with prawda:
- Feminine nominative singular: cała prawda – the whole truth (as a subject)
- Feminine accusative singular: całą prawdę – the whole truth (as an object)

In your sentence, “the whole truth” is the direct object of the verb powiesz, so it must be in the accusative:

Nominative (subject):
- Cała prawda jest skomplikowana. – The whole truth is complicated.
Accusative (object):
- Powiesz jej całą prawdę. – You will tell her the whole truth.

Hence: całą prawdę, not cała prawda.

Can the word order in czy powiesz jej całą prawdę be different?

Yes. Polish has relatively flexible word order, though some options sound more natural than others.

Possible variants (all grammatically correct):

czy powiesz jej całą prawdę – neutral, very natural.
czy jej powiesz całą prawdę – also fine; slight emphasis on jej.
czy całą prawdę jej powiesz – emphasizes całą prawdę; more marked.

However:

czy powiesz całą prawdę jej is technically possible but sounds awkward and unnatural in normal speech. Polish prefers unstressed pronouns like jej earlier in the clause, not at the very end.

For a learner, sticking with czy powiesz jej całą prawdę is safest and most natural.

Could I say Twoja dziewczyna się zastanawia instead of Twoja dziewczyna zastanawia się?

Yes, Twoja dziewczyna się zastanawia is grammatically correct and understandable.

However, for verbs with się, Polish tends to prefer certain word orders. The most neutral for this sentence is:

Twoja dziewczyna zastanawia się...

Other possibilities:

Twoja dziewczyna się zastanawia... – possible; can sound a bit more expressive/emphatic.

What you generally shouldn’t do is separate zastanawia and się too far from each other with other words in between. Keeping się close to the verb is best:

Good: Ona teraz bardzo się zastanawia.
Worse: Ona się teraz bardzo zastanawia (still okay, just a different rhythm).
Avoid putting się at the very beginning or end of the entire sentence.

Is zastanawia się, czy similar to English “is wondering whether”? Could I just say myśli, czy?

Yes, zastanawia się, czy corresponds closely to “is wondering whether / is thinking about whether”.

Twoja dziewczyna zastanawia się, czy...
= Your girlfriend is wondering whether...

You could say myśli, czy, but it has a slightly different feel:

myśli – simply “thinks”, “is thinking”
zastanawia się – “is wondering / is reflecting / is considering”

zastanawia się suggests a more deliberate or uncertain reflection, which matches English “is wondering” quite well. myśli, czy is understandable but a bit less idiomatic; zastanawia się, czy is the most natural in this context.

Could we add ty and say czy ty powiesz jej całą prawdę? What difference would that make?

Yes, you can say:

Twoja dziewczyna zastanawia się, czy ty powiesz jej całą prawdę.

Adding ty is optional, but it has an effect:

Without ty – neutral:
- czy powiesz jej całą prawdę – whether you will tell her the whole truth.
With ty – adds emphasis/contrast:
- czy ty powiesz jej całą prawdę – whether you (as opposed to someone else) will tell her the whole truth, or expressing doubt/amazement that you would do it.

So ty is used mostly for emphasis or contrast, not for basic grammatical necessity.