Falls das Gerät kaputt ist, werden wir es zurückschicken.

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

So:

• Falls das Gerät kaputt ist
• literally: If the device broken is

This is normal German word order after conjunctions like:

• falls = if / in case
• wenn = if / when
• weil = because
• dass = that

Compare:

• Das Gerät ist kaputt. = The device is broken.
• Falls das Gerät kaputt ist ... = If the device is broken ...

In the main statement, ist is in the usual position. In the subordinate clause, it moves to the end.

Because the sentence begins with a subordinate clause:

• Falls das Gerät kaputt ist, ...

After that, the main clause starts, and in a German main clause the conjugated verb must be in position 2.

So the structure is:

1. Falls das Gerät kaputt ist
2. werden
3. wir es zurückschicken

That is why you get:

• Falls das Gerät kaputt ist, werden wir es zurückschicken.

If the main clause came first, you would have:

• Wir werden es zurückschicken, falls das Gerät kaputt ist.

Both are correct.

Both can often be translated as if, but they are not always used in exactly the same way.

In this sentence, falls means something like:

• if
• in case

It often sounds a bit more formal or slightly more specific/conditional than wenn.

So:

• Falls das Gerät kaputt ist, ... = If the device is broken / In case the device is broken

With wenn, you could also say:

• Wenn das Gerät kaputt ist, werden wir es zurückschicken.

That is also correct and very common.

A useful rough idea:

• wenn = the usual everyday if
• falls = if/in case, often a bit more cautious or formal

Because Gerät is a neuter noun in German.

Its article is:

• das Gerät = the device

So in the nominative and accusative singular, the article is das.

German nouns have grammatical gender, and you usually have to learn that together with the noun:

• das Gerät
• not der Gerät
• not die Gerät

Also remember that all German nouns are capitalized, so Gerät starts with a capital letter.

Because kaputt is being used predicatively, not directly before a noun.

In:

• Das Gerät ist kaputt.

kaputt comes after the verb sein and describes the subject. In that position, adjectives do not take adjective endings.

Compare:

• Das Gerät ist kaputt. = The device is broken.
• das kaputte Gerät = the broken device

So:

• after sein -> kaputt
• before a noun -> kaputte / kaputtes / kaputten, depending on the grammar

Werden is used to form the future tense in German.

Here:

• werden wir es zurückschicken
• literally: will we it send back

So this means:

• we will send it back

The structure is:

• werden = conjugated auxiliary verb
• zurückschicken = infinitive at the end

In this sentence:

• werden = first-person plural form
• wir = we

So:

• wir werden = we will

Yes. Very often, German uses the present tense where English would use will.

So these are both possible:

• Falls das Gerät kaputt ist, schicken wir es zurück.
• Falls das Gerät kaputt ist, werden wir es zurückschicken.

The version with werden makes the future meaning more explicit. But in everyday German, the present tense is often enough if the future is already clear from context.

Because this sentence uses the future tense with werden.

In a main clause with werden + infinitive, the conjugated verb werden takes the normal main-clause position, and the full infinitive goes to the end:

• werden wir es zurückschicken

So the pattern is:

• werden
  • subject + other elements + infinitive

Also, zurückschicken is a verb meaning to send back / return.

It is built from:

• zurück = back
• schicken = send

In the infinitive, it appears as one unit:

• zurückschicken

But in a simple finite clause, it separates:

• Wir schicken es zurück.

That is normal for separable verbs.

Es is the pronoun it, and it refers back to das Gerät.

Since Gerät is a neuter noun, the matching pronoun is:

• es = it

So:

• das Gerät -> es

In the sentence:

• werden wir es zurückschicken
• es = the device

Because German pronouns usually come before many other elements in the middle of the clause.

So:

• werden wir es zurückschicken = normal
• werden wir zurückschicken es = not correct

The pronoun es is the direct object, and in a structure like this it normally appears before the final infinitive.

You can think of the clause as:

• werden = conjugated verb in position 2
• wir = subject
• es = object pronoun
• zurückschicken = infinitive at the end

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

So you must write:

• Falls das Gerät kaputt ist, werden wir es zurückschicken.

The comma marks the end of the falls clause and the beginning of the main clause.

German uses commas with subordinate clauses much more consistently and obligatorily than English.

Yes. You can put the main clause first and the subordinate clause second:

• Wir werden es zurückschicken, falls das Gerät kaputt ist.

That means the same thing.

The main difference is emphasis and sentence flow. Starting with Falls das Gerät kaputt ist puts the condition first.

When the subordinate clause comes first, the main clause must begin with the verb:

• ..., werden wir ...

When the main clause comes first, normal word order appears:

• Wir werden ...

In the infinitive, yes:

• zurückschicken

But when the verb is conjugated in a normal main clause, it separates:

• Wir schicken es zurück.

That is because zurückschicken is a separable verb.

So you will see both patterns:

• Infinitive: zurückschicken
• Finite main clause: schicken ... zurück

In your sentence, it stays together because it is an infinitive at the end:

• werden wir es zurückschicken

It is a conditional sentence: it gives a condition and then the result.

Structure:

• Falls das Gerät kaputt ist = condition
• werden wir es zurückschicken = result

So the pattern is:

• If X, then Y

German often forms these with words like:

• wenn
• falls

This is a very common structure, so it is useful to notice the two big grammar features here:

• verb at the end in the subordinate clause
• verb-first after the comma in the main clause because the subordinate clause took position 1