Nie przejmuj się tym egzaminem, masz jeszcze czas na naukę.

Because przejmuj is the imperative form, used for giving a command or advice.

The dictionary form is przejmować się = to worry / to get upset / to be concerned.

In this sentence:

• Nie przejmuj się = Don’t worry

  This is the informal singular form, so you would say it to one person you address as ty.

Compare:

• przejmować się — to worry
• przejmuj się — worry
• nie przejmuj się — don’t worry

So the sentence is speaking directly to someone.

Się is a very common Polish word often called a reflexive particle. In some verbs, it works a bit like oneself, but very often it is just part of the verb and does not translate neatly word-for-word.

Here, the verb is:

• przejmować się — to worry, to be bothered, to get worked up

So się is not optional. You normally learn this verb as a whole expression:

• przejmować się czymś — to worry about something

If you remove się, you change the verb and the meaning.

Because przejmować się requires the instrumental case.

The pattern is:

• przejmować się + instrumental
• martwić się + instrumental is also common

So:

• egzamin = nominative
• egzaminem = instrumental singular

That is why the sentence has:

• tym egzaminem = about this exam

For an English speaker, this can feel strange because English uses a preposition: worry about the exam. In Polish, the case ending does that job.

Because both words have to match in case, gender, and number.

The noun egzamin is:

• masculine
• singular
• instrumental here

So the demonstrative ten changes form too:

• ten egzamin — this exam (nominative)
• tym egzaminem — this exam (instrumental)

This agreement is a basic Polish rule: adjectives, demonstratives, and similar words must match the noun they describe.

Because Polish often omits subject pronouns when they are obvious from the verb form.

In:

• nie przejmuj się
• masz jeszcze czas

the verb endings already tell you the sentence is talking to you (informal singular, ty).

So Polish does not need to say ty unless the speaker wants extra emphasis, contrast, or emotion.

For example:

• Masz czas. — You have time.
• Ty masz czas. — You have time. / It is you who have time.

Here jeszcze means still.

So:

• masz jeszcze czas = you still have time

Depending on context, jeszcze can also mean yet, more, or another, but here still is the natural meaning.

Examples:

• Jeszcze pracuję. — I’m still working.
• Chcesz jeszcze kawy? — Do you want more coffee?
• Jeszcze nie wiem. — I don’t know yet.

Because after na in this meaning, Polish uses the accusative case.

Here the phrase means:

• czas na coś — time for something

So:

• nauka = nominative
• naukę = accusative singular

That is why we get:

• masz jeszcze czas na naukę = you still have time to study / time for studying

This is a very common pattern:

• Mam czas na obiad. — I have time for lunch.
• Nie mam czasu na rozmowę. — I don’t have time for a conversation.

Literally, it is closer to for studying or for study.

Polish often uses a noun where English might prefer an infinitive.

So:

• czas na naukę literally = time for studying / time for study
• natural English translation = time to study

Both ideas are built into the Polish phrase.

Yes. It is informal singular, used when speaking to one person as ty.

Other versions would be:

• Nie przejmujcie się — don’t worry (to more than one person, or informal plural)
• Niech się pan nie przejmuje — don’t worry (formal, to a man)
• Niech się pani nie przejmuje — don’t worry (formal, to a woman)
• Niech się państwo nie przejmują — don’t worry (formal plural)

So the original sentence sounds like something you would say to a friend, classmate, sibling, or someone you speak to informally.

A more natural version would be:

• Nie martw się tym egzaminem
• or more commonly Nie martw się o ten egzamin

Yes, this expresses a very similar idea: Don’t worry about this exam.

Polish has several ways to say this:

• Nie przejmuj się tym egzaminem — Don’t get worked up about this exam / Don’t worry about this exam
• Nie martw się tym egzaminem — very similar
• Nie martw się o ten egzamin — also very common

The original sentence sounds natural and reassuring, with a nuance like don’t stress about it so much.