Wir können die Rücksendung nachverfolgen.

This sentence uses a modal verb construction.

• können = the conjugated modal verb (can / be able to)
• nachverfolgen = the main verb in the infinitive

In a normal main clause, the conjugated verb goes in second position, and the infinitive goes to the end:

• Wir können die Rücksendung nachverfolgen.

This is very common in German:

• Ich kann kommen.
• Sie will gehen.
• Wir müssen warten.

So the structure is:

subject + conjugated modal + object + main verb infinitive

Because modal verbs in German usually take a bare infinitive.

So you say:

• Wir können die Rücksendung nachverfolgen.

not:

• Wir können die Rücksendung zu nachverfolgen. ❌

The same is true with other modal verbs:

• Ich muss arbeiten.
• Du darfst gehen.
• Er will schlafen.

German uses zu with many other verb combinations, but not with the standard modal verbs like können, müssen, wollen, sollen, dürfen, mögen.

Here, können means can / are able to.

So the sentence suggests that we have the ability or possibility to track the return.

Depending on context, English might translate it as:

• We can track the return.
• We’re able to track the return.
• We can trace the return shipment.

It does not necessarily mean physical ability only. It can also mean that the system, service, or process makes it possible.

In customer-service language, Wir können ... often sounds like:

• We are able to ...
• We can do that for you
• We have the option/capability to ...

Because Rücksendung is a feminine noun.

Its dictionary form is:

• die Rücksendung

So in the sentence, the article is die.

German nouns have grammatical gender, and you have to learn the noun together with its article:

• der = masculine
• die = feminine
• das = neuter

So it is best to memorize:

• die Rücksendung = the return / return shipment

It is in the accusative case because it is the direct object of the verb nachverfolgen.

You are tracking what?

• die Rücksendung

That makes it the direct object.

Why does it still look like die? Because for feminine singular nouns, the article is the same in nominative and accusative:

• nominative: die Rücksendung
• accusative: die Rücksendung

So the case changes grammatically, but the form does not change here.

Compare that with a masculine noun, where you can see the difference more clearly:

• nominative: der Versand
• accusative: den Versand

It is a compound noun:

• Rück- = back / return
• Sendung = shipment / dispatch / consignment

So Rücksendung literally means something like:

• return shipment
• returned parcel
• return

In real usage, it can refer to:

• the item being sent back
• the shipment process of returning it
• the return as a logistics event

In online shopping and customer support, Rücksendung is very common.

Not exactly.

• verfolgen often means to follow, to pursue, or to track in a broader sense
• nachverfolgen often means to trace, to track step by step, or to follow the progress/status of something

In shipping or logistics, nachverfolgen is especially natural for things like:

• parcels
• returns
• deliveries
• order status

So in this sentence, nachverfolgen has the sense of:

• checking where the return is
• tracing its progress in the system
• following its shipment status

That is why it fits very well here.

Grammatically, wir simply means we.

In context, though, it often refers to:

• a company
• a customer support team
• a service department
• a shop or seller

So in a sentence like this, wir may not mean a small personal we. It may be the company speaking in its official voice, just like English customer support might say:

• We can track the return for you.

So the tone is often professional or service-oriented.

For a yes/no question, German usually puts the conjugated verb first:

• Können wir die Rücksendung nachverfolgen?

That means:

• Can we track the return?

If you want a statement, the finite verb stays in second position:

• Wir können die Rücksendung nachverfolgen.

So the main change is the position of können.

In a subordinate clause, the conjugated verb usually moves to the end.

So you get:

• ..., weil wir die Rücksendung nachverfolgen können.

Notice what happened:

• in the main clause: Wir können die Rücksendung nachverfolgen.
• in the subordinate clause: ..., weil wir die Rücksendung nachverfolgen können.

With a modal construction, both verbs are near the end, and können comes last in this kind of clause.

This is a very common pattern in German.

The main pronunciation difficulty is the umlauts:

• ö in können
• ü in Rücksendung

A rough guide:

• können: the ö has no exact English equivalent; make a short e-like sound while rounding your lips
• Rück-: the ü also has no exact English equivalent; try saying ee while rounding your lips

A very rough English-friendly approximation might be:

• können ≈ KER-nen with rounded lips
• Rücksendung ≈ RUEK-sen-doong (but this is only approximate)

Also note:

• ck in Rück makes the vowel short
• -ung is pronounced with the typical German ng sound, not a hard g

If you want to sound more natural, it helps to learn können and Rücksendung by listening rather than relying only on English-style approximations.