Bevor das Seminar beginnt, schreibe ich meinen Namen auf das Namensschild.

Because bevor introduces a subordinate clause. In German, the conjugated verb normally goes to the end of a subordinate clause.

• Main clause: Das Seminar beginnt.
• Subordinate clause with bevor: bevor das Seminar beginnt

This is a very common pattern with words like bevor, weil, dass, wenn, and obwohl.

German uses a comma to separate a subordinate clause from a main clause.

So in:

Bevor das Seminar beginnt, schreibe ich meinen Namen auf das Namensschild.

the comma marks the end of the bevor clause and the start of the main clause.

This comma is required in standard German.

Because the sentence begins with the subordinate clause:

Bevor das Seminar beginnt, ...

That whole clause takes up the first position in the sentence. In a German main clause, the conjugated verb must come in the second position, so you get:

• 1st position: Bevor das Seminar beginnt
• 2nd position: schreibe
• then the subject: ich

So:

Bevor das Seminar beginnt, schreibe ich ...

If you started with the subject instead, it would be:

Ich schreibe meinen Namen auf das Namensschild, bevor das Seminar beginnt.

Both are correct.

Because Namen is the direct object of schreibe. Direct objects take the accusative case.

Name is masculine, so the possessive mein changes in the accusative masculine:

• Nominative: mein Name
• Accusative: meinen Namen

So:

• Mein Name ist Anna.
• Ich schreibe meinen Namen.

Also note that Name is one of the nouns that often has an extra -n in certain forms, which is why you see Namen here.

Namensschild is a compound noun:

• Name = name
• Schild = sign / label / badge

Together, Namensschild means name tag or name badge.

The gender comes from the last part of the compound, which is Schild, and Schild is neuter:

• das Schild
• therefore das Namensschild

This is a useful rule in German: the final part of a compound noun usually determines the gender.

Here auf is used with the idea of writing something onto a surface. German often uses the accusative after two-way prepositions like auf when there is direction or a result affecting a place/surface.

So:

• auf das Namensschild schreiben = write onto the name tag
• auf dem Namensschild stehen = be written on the name tag

In this sentence, the action is directed onto the badge, so das Namensschild is in the accusative.

No. In this sentence, auf is a preposition, not a separable prefix.

Here the structure is:

• schreiben = to write
• auf das Namensschild = onto the name tag

So the meaning is literally to write something onto the badge.

That is different from aufschreiben, which usually means to write down or to note down:

• Ich schreibe mir die Telefonnummer auf. = I write down the phone number.

So schreibe ... auf das Namensschild is not the same as schreibe ... auf as a separable verb.

German often uses the present tense to talk about future events when the time is clear from context.

In this sentence, before the seminar begins already makes the time frame clear, so German does not need a special future form.

That is very normal:

• Morgen gehe ich nach Berlin. = Tomorrow I’m going to Berlin.
• Bevor das Seminar beginnt, schreibe ich meinen Namen ...

You could use werden, but it would usually sound less natural here.

Yes, often you can.

• beginnen = to begin
• anfangen = to start / begin

So this would also work:

Bevor das Seminar anfängt, schreibe ich meinen Namen auf das Namensschild.

Both are common. beginnen can sound a little more formal or neutral, while anfangen is often a bit more everyday.

Yes. You can put the main clause first:

Ich schreibe meinen Namen auf das Namensschild, bevor das Seminar beginnt.

That may feel more natural to some English speakers because it matches English order more closely.

Both versions mean the same thing, but the emphasis changes slightly:

• Bevor das Seminar beginnt, ... emphasizes the time condition first.
• Ich schreibe ..., bevor das Seminar beginnt. emphasizes the action first.

Bevor is a conjunction meaning before when it introduces a clause with a verb.

• Bevor das Seminar beginnt = before the seminar begins

Vor is usually a preposition, used with a noun phrase instead of a full clause:

• vor dem Seminar = before the seminar

So:

• Bevor das Seminar beginnt, ... → full clause
• Vor dem Seminar ... → noun phrase

Both can be correct, but they are built differently.

Because Seminar is simply a neuter noun in German, so its article is das.

Like many nouns, its gender has to be learned as part of the word:

• das Seminar
• das Buch
• der Tisch
• die Lampe

There is not always a logical reason that helps English speakers, so it is best to memorize the noun together with its article.

Yes. Auf das is often contracted to aufs in normal German:

• auf das Namensschild
• aufs Namensschild

Both are correct. Aufs is very common in everyday speech and writing.

So this version is also natural:

Bevor das Seminar beginnt, schreibe ich meinen Namen aufs Namensschild.