Beställningen ligger redan i paketboxen utanför butiken.

Because -en is the definite article suffix in Swedish. Instead of using a separate word like the before the noun, Swedish often adds the definite ending to the noun itself.

• beställning = order
• beställningen = the order

So Beställningen means the order.

Swedish usually puts the at the end of the noun as a suffix.

In this sentence:

• beställningen = the order
• paketboxen = the parcel locker / the package box
• butiken = the shop / the store

This is very normal in Swedish. English uses a separate word (the), but Swedish often attaches it to the noun.

Swedish often uses position verbs where English would simply use is.

Here, ligger literally means lies / is lying, but in this kind of sentence it often just means is located or is there.

So:

• Beställningen ligger i paketboxen = The order is in the parcel locker

Swedish prefers verbs like:

• ligga = lie, be lying
• stå = stand, be standing
• sitta = sit, be sitting

For objects in containers, enclosed spaces, or places where they are thought of as resting, ligga is very common.

This is normal Swedish word order.

In a main clause, Swedish usually has:

1. the first element
2. the finite verb
3. sentence adverbs like redan, inte, ofta, etc.

So:

• Beställningen = first element
• ligger = finite verb
• redan = adverb

That is why redan comes after ligger:

• Beställningen ligger redan i paketboxen

This is a very common pattern in Swedish.

Redan means already.

It shows that the action or result has happened earlier than expected, or that it is true now sooner than the listener might have thought.

So here it suggests:

• the order has already been placed in the parcel locker
• it is there now

Because i means in / inside, and a parcel locker is thought of as an enclosed space.

• i paketboxen = in the parcel locker

If you said på paketboxen, that would mean on the parcel locker, as if something were physically sitting on top of it.

So i is the natural choice here.

Yes, it is one word, and that is very typical in Swedish.

Swedish often forms compound nouns by joining words together:

• paket = package / parcel
• box = box
• paketbox = parcel locker / package box
• paketboxen = the parcel locker

English sometimes uses separate words where Swedish prefers one combined noun.

Utanför butiken means outside the shop/store.

Here, butiken already means the shop, so no extra word is needed.

• utanför = outside
• butiken = the shop

You would only say something like den butiken if you wanted to emphasize that shop specifically:

• utanför den butiken = outside that shop

But in your sentence, plain utanför butiken is the natural choice.

Because the sentence refers to a specific shop, not just any shop.

• butik = shop / store
• butiken = the shop / the store

Swedish uses the definite form when the listener is expected to know which place is meant, or when the place is identifiable from context.

Yes, you can, and it would be understood. It means something like The order is already in the parcel locker.

But ligger sounds more idiomatic in many contexts, because Swedish often describes the physical location of things with verbs like ligga rather than just vara.

So:

• är = possible, understandable
• ligger = often more natural for an object located somewhere

In Swedish, yes/no questions usually put the verb first.

So:

• Beställningen ligger redan i paketboxen utanför butiken. becomes
• Ligger beställningen redan i paketboxen utanför butiken?

That is a very common Swedish pattern:

• statement: Subject + verb
• yes/no question: Verb + subject

You would usually place inte after the finite verb, in the same area where redan appears.

For example:

• Beställningen ligger inte i paketboxen utanför butiken.
  = The order is not in the parcel locker outside the shop.

If you want both already and not, the exact meaning depends on word order, but a common version is:

• Beställningen ligger inte redan i paketboxen...

However, in everyday Swedish, people may rephrase the sentence depending on what they want to emphasize.

A rough English-style approximation is something like be-STELL-ning-en, but that is only approximate.

A few helpful points:

• ä sounds somewhat like the vowel in bed, though not exactly the same
• the stress is mainly on ställ
• ng in -ning sounds like the ng in sing

So the word has three main parts:

• be
• ställ
• ningen

If you are learning pronunciation, it is especially useful to listen for the stressed middle part: ställ.