Learn Hardcore German: Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel. - Before the exam the pupil secretly writes himself a cheat sheet.

It is usually a written exam, often longer and more formal.
You’ll see it in schools and especially at universities (end-of-semester written exams are typically called Klausuren).
A small quiz or informal test might be called Test or Klassenarbeit, but a serious, scheduled, written exam is often a Klausur.

So „Vor der Klausur“ is best understood as “before the (written) exam”, not just any random test.

Why is it „Vor der Klausur“ and not „vor die Klausur“ or „vor dem Klausur“?

There are two things going on: the preposition vor and the noun Klausur.

The preposition „vor“ is a two-way preposition (Wechselpräposition):
- With dative, it usually expresses location or time.
- With accusative, it usually expresses movement towards something.
Here we are talking about a time (“before the exam”), not moving anywhere, so dative is required.
„Klausur“ is feminine:
- Nominative: die Klausur
- Dative singular (feminine): der Klausur

So:

Vor der Klausur = before the exam (correct: dative feminine)
Vor die Klausur would suggest movement to a place in front of the exam, which makes no sense in this context.
vor dem Klausur is wrong because Klausur is not masculine/neuter; it’s feminine, so dative is der, not dem.

Why does the sentence start with „Vor der Klausur“? Could I also say „Der Schüler schreibt sich vor der Klausur heimlich einen Spickzettel“?

Yes, you can absolutely say:

Der Schüler schreibt sich vor der Klausur heimlich einen Spickzettel.

German main clauses are verb-second (V2), but almost anything can be put in the first position (the Vorfeld) for emphasis or topic-focus. In your original sentence:

Vor der Klausur (time information) is in first position (topic: when).
schreibt is second (the finite verb).
The rest follows: sich der Schüler heimlich einen Spickzettel.

If you start with Der Schüler, the focus is more on who is doing it.
If you start with Vor der Klausur, the focus is more on when it happens.

Both are grammatically correct; the difference is emphasis and information structure, not basic meaning.

What does „schreibt sich“ mean here? Why is it reflexive?

The verb is schreiben (“to write”), and sich is a reflexive pronoun.

With two objects, German often uses a dative pronoun to show that the subject does something for themself:

Ich schreibe mir einen Spickzettel. – I write myself a cheat sheet (for my own use).
Du schreibst dir einen Spickzettel.
Der Schüler schreibt sich einen Spickzettel.

So „schreibt sich … einen Spickzettel“ roughly means:

“writes (for himself) a cheat sheet”, or
“writes himself a cheat sheet”.

The reflexive pronoun basically says: the cheat sheet is for the student’s own benefit.

Do I have to use „sich“ here? What’s the difference between „schreibt einen Spickzettel“ and „schreibt sich einen Spickzettel“?

Both are possible:

Mit „sich“:
- Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel.
- Emphasizes that he writes it for himself, for his own use.
- Very natural with this meaning.
Ohne „sich“:
- Vor der Klausur schreibt der Schüler heimlich einen Spickzettel.
- Grammatically fine.
- Still usually understood that it’s for himself (because who else?), but the “for himself” part is not highlighted.

In practice, using „sich“ is more idiomatic here. Dropping it makes the sentence slightly more neutral, maybe a bit less personal.

Is „sich“ accusative or dative in this sentence?

In this pattern it functions as dative.

The structure is:

jemand schreibt sich (Dat.) etwas (Akk.)

Examples:

Ich schreibe mir einen Spickzettel.
– mir = dative, einen Spickzettel = accusative direct object.
Der Schüler schreibt sich einen Spickzettel.

For the 3rd person, the reflexive pronoun „sich“ looks the same in accusative and dative form, so you can’t see the case from the form alone.
You recognize it from the verb pattern: whenever you have two objects, one pronoun and one full noun, the pronoun is typically dative and the full noun is accusative.

What exactly is a „Spickzettel“?

A Spickzettel is:

literally: a cheat sheet – a small piece of paper with notes to cheat in a test.
from the verb spicken = to cheat by peeking at hidden notes or someone else’s work.

Typical associations:

Tiny piece of paper hidden in a pencil case, sleeve, under the desk, etc.
Definitely dishonest in a school or exam context.

So the sentence describes a pupil secretly writing himself an illegal little cheat sheet before the exam.

Why is it „einen Spickzettel“ and not „ein Spickzettel“?

Because Spickzettel is:

Masculine: der Spickzettel
In this sentence, it’s the direct object of schreibt → accusative case.
Masculine accusative singular of ein is einen.

So:

Nominative: ein Spickzettel – a cheat sheet (as a subject)
Accusative: einen Spickzettel – a cheat sheet (as an object)

Here, he writes what? → einen Spickzettel (accusative).

Why is it „der Schüler“ and not „den Schüler“?

Der Schüler is the subject of the sentence:

Wer schreibt sich heimlich einen Spickzettel?
→ Der Schüler.

Subjects in German normally take the nominative case.
Nominative singular masculine article = der.

Den Schüler would be accusative, which you would use if the pupil were the object, for example:

Der Lehrer tadelt den Schüler. – The teacher scolds the pupil.

What does „heimlich“ mean, and where can it go in the sentence?

Heimlich is an adverb and means:

secretly, on the sly, without being noticed.

In your sentence:

Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel.

This is a very natural position for manner adverbs (how something is done), placed after the subject/objects begin to appear.

Other possible positions (all grammatically OK, with slight changes in emphasis):

Vor der Klausur schreibt sich der Schüler einen Spickzettel heimlich.
(Unusual; heimlich sounds tacked on for emphasis.)
Vor der Klausur schreibt der Schüler sich heimlich einen Spickzettel.
(Also common; here „sich“ comes earlier as a pronoun.)

General rules:

Short pronouns tend to appear earlier, close to the verb.
Adverbs like heimlich often stand before the main object noun or right after the subject, depending on what you want to emphasize.

Could I say „Vor der Klausur schreibt der Schüler sich heimlich einen Spickzettel“ instead? Is that better German?

Yes, that is actually a very natural word order:

Vor der Klausur schreibt der Schüler sich heimlich einen Spickzettel.

Two tendencies in German:

The finite verb is always second.
Object pronouns (like sich) tend to come before full noun objects (einen Spickzettel).

So in many contexts, a “default-sounding” order would be:

Vor der Klausur schreibt der Schüler sich heimlich einen Spickzettel.

Your original:

Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel.

is also correct, just somewhat more marked in terms of information flow (focus slightly more on the reflexive action early on). Both are fine; native speakers will use both.

Why is the verb in the present tense (schreibt), even though it’s about something that will happen in the future (“before the exam”)?

German often uses the present tense to talk about the near future, especially when the time is clear from context:

Morgen schreibe ich eine Klausur. – I’m writing / I’ll write an exam tomorrow.
Nächste Woche fahren wir nach Berlin. – We’re going / will go to Berlin next week.

Here:

Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel.

Depending on context, this can be understood as:

A general habit: Before exams, the student secretly writes himself a cheat sheet.
Or as a planned/future action in a narrative: Before the exam, the pupil will secretly write himself a cheat sheet.

So present tense + time expression „vor der Klausur“ is enough to give it a future meaning in English if needed. German doesn’t need „wird schreiben“ here.

Could I replace „schreibt“ with „macht“ or „erstellt“? For example: „macht sich einen Spickzettel“?

Yes, but with slight differences in nuance:

schreibt sich einen Spickzettel
- Most natural, because a cheat sheet is written.
- Emphasizes the act of writing.
macht sich einen Spickzettel
- Also idiomatic: “makes himself a cheat sheet.”
- More general: focuses on creating it, not specifically on writing.
erstellt sich einen Spickzettel
- Grammatically OK, but sounds more formal/technical (like “creates/prepares a document”).
- Not wrong, but less natural in a school-cheating context; schreibt or macht would be more typical.

So the original „schreibt sich einen Spickzettel“ is stylistically the best choice here.

Why do we say „vor der Klausur“ and not „bevor der Klausur“?

Because „vor“ and „bevor“ are different types of words:

vor = preposition
- Must be followed by a noun (with an article, if needed) in dative/accusative:
  - vor der Klausur, vor dem Haus, vor dem Essen.
bevor = subordinating conjunction
- Must be followed by a clause (subject + finite verb at the end):
  - bevor die Klausur beginnt – before the exam begins
  - bevor er in die Schule geht – before he goes to school

So you can say either:

Vor der Klausur schreibt sich der Schüler heimlich einen Spickzettel.
Bevor die Klausur beginnt, schreibt sich der Schüler heimlich einen Spickzettel.

But not „bevor der Klausur“ – that’s mixing conjunction usage with a noun phrase, which is ungrammatical.