Hon har alltid plåster i väskan, men idag hittar hon inget plåster där.

In Swedish, plåster can be used as a “generic supply” noun, similar to talking about having band-aids available in general. So Hon har alltid plåster i väskan means she always has band-aids (some band-aids) in her bag, without focusing on exactly one item.

If you do want to specify number, Swedish can do that too:

• ett plåster = one band-aid
• två plåster = two band-aids
• plåstret = the band-aid (specific one)
• plåstren = the band-aids (specific set)

Form-wise, plåster is special because indefinite singular and indefinite plural look the same:

• ett plåster (singular)
• (flera) plåster (plural)

In your sentence, it’s best understood as “some / any band-aids” (unspecified quantity). Context and determiners (like ett, många, inga) usually tell you which reading is intended.

Swedish often uses the definite form (väskan) when the thing is identifiable from context—here, it’s clearly “her bag” in the situation.

• i väskan = in the bag (contextually known: her bag)
• i sin väska = in her (own) bag (adds clarity/emphasis that it’s her own, not someone else’s)
• i en väska = in a bag (any bag; not assumed to be a specific known one)

So i väskan is very natural in everyday Swedish.

In Swedish main clauses, sentence adverbs like alltid, ofta, inte, ju, etc. typically come after the finite verb.

So:

• Hon har alltid plåster ... (finite verb har
  • adverb alltid)

If you placed alltid before har in a normal main clause, it would usually sound wrong or very marked.

This is the Swedish V2 rule in main clauses: the finite verb must be in position 2.

When you put idag first, it takes position 1, so the verb must come next, and the subject moves after the verb:

• Idag (position 1) + hittar (position 2) + hon (after the verb)

Compare:

• Hon hittar inget plåster där idag. (subject first)
• Idag hittar hon inget plåster där. (time first → inversion)

Because Swedish commonly uses ingen / inget / inga to negate a noun phrase (meaning “no / none”).

• ingen with common gender nouns (en-words)
• inget with neuter nouns (ett-words)
• inga with plural nouns

Since plåster is an ett-word (ett plåster), you get:

• inget plåster = no band-aid / no band-aids

You can also use inte with something like något:

• Hon hittar inte något plåster där. That’s grammatical, but hon hittar inget plåster där is usually the more direct/idiomatic choice.

You choose based on the noun’s grammatical category:

• ett plåster → neuter → inget plåster
• if it were an en-word, you’d use ingen (e.g., ingen nyckel)
• if it’s clearly plural, you use inga (e.g., inga plåster = no band-aids at all, explicitly plural)

So the key is: plåster is neuter (ett).

där means “there” and points back to the previously mentioned place: i väskan.

It helps avoid repeating the full phrase:

• ... men idag hittar hon inget plåster där. = ...but today she finds no band-aid(s) there (i.e., in the bag).

You could also repeat the place, but it’s heavier:

• ... men idag hittar hon inget plåster i väskan.

You can say ... men idag hittar hon inget där, and it would mean “she finds nothing there.” But that’s broader: nothing at all.

Repeating the noun keeps the meaning specific:

• inget plåster = no band-aid(s), specifically

So the repetition is for clarity and focus.

Because men is linking two full main clauses, each with its own subject + verb:

• Hon har ...
• idag hittar hon ...

Using a comma here is very common in Swedish writing to mark that boundary. In more casual writing, commas are sometimes omitted, but the comma is standard and clear in this kind of sentence.