Learn Hardcore Indonesian: Jika kamu gelisah sebelum ujian, itu belum tentu berarti kamu tidak siap. - If you are restless before an exam, that does not necessarily mean you are not ready.

Jika is a bit more formal and often used in written language, explanations, instructions, or essays.
Kalau is more informal and very common in everyday speech.

You could say:

Kalau kamu gelisah sebelum ujian, itu belum tentu berarti kamu tidak siap.

This would sound more conversational but is still correct. The meaning is the same.

Is kamu polite? When should I use kamu versus Anda?

Kamu means you and is:

Neutral–informal
Used with friends, classmates, people your age, or younger people
Often used in textbooks for simplicity

Anda:

More formal and polite
Used with strangers, customers, in service situations, in formal writing, or when you want to show respect

The sentence with Anda:

Jika Anda gelisah sebelum ujian, itu belum tentu berarti Anda tidak siap.

That sounds more formal and polite, for example in a brochure or a lecture. With a friend, kamu is more natural.

What exactly does gelisah mean? Is it the same as nervous?

Gelisah describes a restless, uneasy, worried feeling. It’s close to anxious, restless, or on edge.

Nuances:

Emotional / mental uneasiness: worried, can’t relax
Sometimes also physical restlessness: can’t sit still, fidgeting

Related words:

Gugup = nervous in the sense of stage fright, shy/tongue-tied
Cemas = anxious, worried, often stronger or more serious
Khawatir = worried, concerned

In this context, gelisah sebelum ujian matches English nervous before an exam quite well.

What does belum tentu mean literally, and what nuance does it add?

Literally:

belum = not yet
tentu = certain, sure

So belum tentu = not yet certain, not necessarily.

Nuance:

It expresses uncertainty or lack of automatic connection:

Itu belum tentu berarti... ≈ That doesn’t necessarily mean…
It softens the statement. Instead of saying it does not mean, it says it’s not certain that it means.

So the sentence is gently saying: being anxious before an exam does not automatically / necessarily mean you are unprepared.

Why is there an itu in itu belum tentu berarti? What does itu refer to?

Itu here is a pronoun, like that in English. It refers back to the whole previous clause:

Jika kamu gelisah sebelum ujian,
itu (that situation / that fact) belum tentu berarti kamu tidak siap.

So itu stands for being anxious before the exam.

You can think of it as:

If you are anxious before an exam, that doesn’t necessarily mean you’re not ready.

Can I omit itu and just say belum tentu berarti?

Yes, you can say:

Jika kamu gelisah sebelum ujian, belum tentu berarti kamu tidak siap.

This is still understandable and used in speech. However:

With itu, the sentence is clearer and more natural, especially in writing, because the subject (that) is explicit.
Without itu, it sounds a bit more casual and less complete.

Both are grammatically acceptable; itu simply makes the structure smoother and clearer.

What is the role of berarti here, and how does it work grammatically?

Berarti is a verb that means to mean or to have the meaning of.

Pattern:

X berarti Y = X means Y

In the sentence:

itu belum tentu berarti kamu tidak siap
itu = that (being anxious before the exam)
berarti = means
kamu tidak siap = you are not prepared

So: that does not necessarily mean (that) you are not prepared.

Grammatically, berarti acts like a normal verb; it does not need a linking verb like is.

What is the difference between belum tentu berarti and tidak berarti?

tidak berarti = does not mean / has no meaning
- Strong, definite: It does not mean that.
belum tentu berarti = does not necessarily mean / is not definitely meaning
- Softer, probabilistic: It may or may not mean that; it’s not certain.

Compare:

Jika dia terlambat, itu tidak berarti dia malas.
= If he is late, it does not mean he is lazy. (strong denial)
Jika dia terlambat, itu belum tentu berarti dia malas.
= If he is late, that doesn’t necessarily mean he is lazy. (more balanced, allows for possibility)

Why is tidak siap used instead of belum siap?

Siap = ready / prepared
Tidak siap = not ready / unprepared (no readiness)
Belum siap = not yet ready (may be ready later; there’s an expectation of becoming ready)

Here the idea is:

The anxiety does not prove that you are unprepared in general.

So tidak siap (unprepared) fits better. If you said belum siap, it would lean toward:

you are not ready yet, but you might be later

which is a slightly different meaning.

How is sebelum ujian working grammatically? Why is there no tense marker like “will be”?

Sebelum = before, and ujian = exam.
Sebelum ujian = before the exam.

Indonesian usually does not mark tense on verbs. Time is shown by:

Time words (kemarin, besok, nanti, sekarang, tadi, etc.)
Context

So:

Jika kamu gelisah sebelum ujian can mean:
- If you are anxious before the exam (general habit)
- If you get anxious before the exam (future)
- If you feel anxious before an exam (timeless/general)

English needs are / get / will be, but Indonesian just uses kamu gelisah without a tense change.

What does ujian mean exactly? Is it the same as tes?

Ujian = exam, test, often more formal or important, e.g.:

school exams
university exams
certification exams

Tes:

Also test, often smaller or more casual:
- a quiz,
- a quick test,
- a medical test,
- a practice test.

In many contexts, ujian and tes overlap, but:

sebelum ujian often suggests a significant exam (e.g., midterms, finals).
sebelum tes kecil would suggest a small quiz.

Could I replace jika with ketika in this sentence?

You could say:

Ketika kamu gelisah sebelum ujian, itu belum tentu berarti kamu tidak siap.

But the nuance changes:

Jika = if / whenever (conditional)
- Focus: condition and possible result.
Ketika = when (time reference)
- Focus: time something happens.

In this sentence, we are talking about a condition (being anxious) and what it does or does not imply, so jika is more natural.

With ketika, it sounds more like you’re describing what is true at the time when you feel anxious, not a general conditional rule. The original with jika is more idiomatic for stating this kind of general idea.