Jag väntar på ett paket som ska levereras i dag.

In Swedish, vänta usually takes the preposition på when you’re waiting for something:

• Jag väntar på bussen. = I’m waiting for the bus.
  Without på, vänta often sounds incomplete unless the thing you’re waiting for is implied or the structure changes (e.g., Vänta! = Wait!).

Because som introduces a relative clause (like English that/which):

• ett paket som ska levereras i dag = a package that is going to be delivered today
  att is used with infinitives (“to …”) or subordinate clauses after certain verbs/adjectives, not for relative clauses:
• Jag hoppas att… = I hope that…

ska often expresses something scheduled, intended, or expected to happen—very natural for deliveries and plans:

• som ska levereras i dag = that is to be delivered / that’s scheduled to be delivered today
  kommer att is more like “will” in the sense of a prediction or future statement and can work too, but it often feels slightly more like forecasting:
• som kommer att levereras i dag = that will be delivered today (sounds a bit more neutral/predictive)

Yes. This is the s-passive (passive with -s):

• leverera (to deliver) → levereras (is delivered / will be delivered)
  Swedish commonly uses -s to form passives, especially in formal or neutral statements.

You can, but it’s usually less idiomatic here.

• ska levereras focuses on the action “to be delivered” and is the standard for deliveries.
• ska bli levererat is also passive-ish, but bli + participle often emphasizes a change of state (“become delivered”), which can sound clunkier for routine actions.

Yes, it can move, but placement changes emphasis and sometimes sounds more or less natural. Common options:

• Jag väntar på ett paket som ska levereras i dag. (neutral)
• I dag väntar jag på ett paket som ska levereras. (emphasizes “today”)
  Inside the relative clause, i dag often comes at the end as shown.

Relative clause structure is basically: som + verb phrase.
Here the verb phrase is ska levereras (modal + passive). Swedish keeps the modal before the main verb, just like English:

• ska
  • levereras = “is going to be delivered / is to be delivered”

Not naturally here. vilket usually refers to an entire preceding clause/idea (“which” = “which fact/thing”), or it’s used with ett-words in certain relative structures—but for “a package that…”, som is the normal choice:

• ett paket som… ✅
• ett paket vilket… ❌ (sounds wrong in modern Swedish)

It can mean either, depending on context. Often it implies “I’m expecting a package” (it’s on its way), not necessarily that you are physically standing somewhere waiting. If you want to stress physical waiting, you might add context:

• Jag sitter hemma och väntar på ett paket… = I’m sitting at home waiting for a package…

A common Swedish way is to keep the relative clause, as in your sentence. If you truly want an infinitive idea, you might say:

• Jag väntar på att ett paket ska levereras i dag. = I’m waiting for a package to be delivered today.
  Here väntar på att introduces a clause (not a relative clause), and ett paket becomes the subject of that clause.

Because vänta på is the fixed combination, and then att introduces the subordinate clause:

• vänta på + att-clause = “wait for (it) that …” → idiomatically “wait for … to …”
  So på belongs to vänta, not to att.

Both can translate to “be delivered,” but they differ in feel:

• levereras (s-passive) is often neutral, factual, and common for schedules/processes.
• bli levererad can feel more event-focused (“end up getting delivered”), sometimes used if delivery is uncertain or contrasted. For routine “is scheduled to be delivered,” levereras is the default.

Yes, if it’s a specific, known package (e.g., the one you ordered):

• Jag väntar på paketet som ska levereras i dag. = I’m waiting for the package that’s to be delivered today.
  Using ett paket is more like “a package (one of them / not yet identified)” or just more general. In real life, both occur; paketet often sounds very natural if you mean “my package.”