Wenn du aus der Ausfahrt kommst, musst du den Blinker rechtzeitig setzen.

Wenn introduces a subordinate clause and here means when in the sense of whenever / at the moment that.

So:

• Wenn du aus der Ausfahrt kommst = When you come out of the driveway/exit
• musst du den Blinker rechtzeitig setzen = you have to signal in good time

A learner often asks whether wenn means if or when. In German, it can mean both depending on context. In this sentence, it clearly means when.

Because wenn du aus der Ausfahrt kommst is a subordinate clause. In German, the conjugated verb usually goes to the end of a subordinate clause.

Compare:

• Main clause: Du kommst aus der Ausfahrt.
• Subordinate clause: wenn du aus der Ausfahrt kommst

That is one of the most important word-order rules in German.

In German, a subordinate clause is normally separated from the main clause by a comma.

So:

• Wenn du aus der Ausfahrt kommst, ← subordinate clause
• musst du den Blinker rechtzeitig setzen. ← main clause

Unlike in English, this comma is not optional here.

Because the sentence begins with the wenn-clause, and in German the main clause still follows the verb-second rule.

The first position in the whole sentence is taken by:

• Wenn du aus der Ausfahrt kommst

Then the conjugated verb of the main clause must come next:

• musst

Then comes the subject:

• du

So the structure is:

• Wenn du aus der Ausfahrt kommst, musst du ...

If you started with the main clause instead, you would say:

• Du musst den Blinker rechtzeitig setzen, wenn du aus der Ausfahrt kommst.

Der Ausfahrt is dative singular.

That is because of the preposition aus, which always takes the dative.

• aus der Ausfahrt = out of the driveway/exit

The noun is:

• die Ausfahrt (nominative)
• der Ausfahrt (dative)

So this is a good example of a fixed preposition-case combination:

• aus + dative

Ausfahrt can mean different things depending on context, for example:

• exit (such as a road exit)
• driveway
• way out

In this sentence, it most likely means something like:

• driveway
• exit from a property/parking area

So aus der Ausfahrt kommen means to come out of the driveway/exit.

German often uses traffic-related words a bit more broadly than English, so the exact best translation depends on the situation.

Because Blinker is the direct object of setzen, so it is in the accusative case.

The noun is:

• der Blinker = nominative
• den Blinker = accusative

So:

• du setzt den Blinker
• you use/set the turn signal

Even though English might not say set the indicator, German commonly uses den Blinker setzen in driving contexts.

Der Blinker means the turn signal / indicator of a vehicle.

Depending on the variety of English:

• American English: turn signal
• British English: indicator

In everyday German, Blinker is very common and natural.

Yes, it sounds unusual if translated word for word. German often says:

• den Blinker setzen

Literally that is something like to set the indicator, but natural English would usually be:

• to signal
• to put your indicator on
• to use the turn signal

This is a good example of why direct word-for-word translation can be misleading. The German expression is idiomatic.

You may also hear:

• den Blinker anmachen
• blinken

But den Blinker setzen is standard and especially common in rule-based or driving-instruction language.

Rechtzeitig means in time, early enough, or with enough warning.

In this traffic context, it means you should signal before coming out, not at the last second.

So:

• den Blinker rechtzeitig setzen = to signal in good time / early enough

It does not just mean eventually or at some point. It specifically suggests the action should happen soon enough to be useful and safe.

German adverbs often appear before the infinitive or other final verb elements near the end of the clause.

In this sentence:

• musst = conjugated modal verb
• setzen = infinitive at the end
• rechtzeitig comes before that infinitive

So:

• musst du den Blinker rechtzeitig setzen

That word order is very natural in German.

You could think of the sentence frame as:

• musst ... setzen

with the other information placed between them.

Because musst is a modal verb. With modal verbs in German, the second verb usually goes to the end in the infinitive form.

So:

• du musst setzen
• you must set/use

In the full sentence:

• musst du den Blinker rechtzeitig setzen

This is a standard German pattern:

• Ich muss gehen.
• Wir wollen essen.
• Er kann fahren.

The modal verb is conjugated, and the main action verb goes to the end.

Yes, but it would change the nuance.

• musst = must / have to
• sollst = should / are supposed to

In a driving-rule context, musst sounds stronger and more like an obligation or requirement.

So this sentence means it is something you are required to do, not just recommended to do.

Du is the informal singular you.

This is common in:

• teaching materials
• driving instruction
• general rules addressed directly to one person
• everyday speech

A more formal version would use Sie:

• Wenn Sie aus der Ausfahrt kommen, müssen Sie den Blinker rechtzeitig setzen.

Both are grammatically correct; the difference is formality.

Yes. Aus der Ausfahrt kommen is literally to come out of the driveway/exit.

In English, depending on the context, we might more naturally say:

• when you pull out of the driveway
• when you come out of the exit
• when you exit the driveway

So the German verb kommen is straightforward, but the best English translation may vary according to the situation.

Yes. German allows both of these:

• Wenn du aus der Ausfahrt kommst, musst du den Blinker rechtzeitig setzen.
• Du musst den Blinker rechtzeitig setzen, wenn du aus der Ausfahrt kommst.

They mean essentially the same thing.

The first version puts more emphasis on the situation:

• When you come out of the driveway...

The second begins with the obligation:

• You must signal...

Both are natural.

Grammatically, it uses the present tense, but German often uses the present tense for future meaning when the context is clear.

So although the verbs are present tense:

• kommst
• musst

the meaning is something like:

• Whenever you come out of the driveway, you must signal in good time or
• When you come out of the driveway, you will need to signal in good time

This is very normal in German.

A helpful breakdown is:

1. Wenn du aus der Ausfahrt kommst
   = subordinate clause introduced by wenn

2. musst du den Blinker rechtzeitig setzen
   = main clause with a modal verb

More structurally:

• Wenn
  • subject + prepositional phrase + verb
• then comma
• then main clause with verb-second order

So you can see several core German patterns in one sentence:

• subordinate clause verb at the end
• comma before the main clause
• main clause verb-second
• modal verb + infinitive at the end
• preposition aus
  • dative
• direct object in the accusative