Learn Hardcore Swedish: Morfar säger att barnbarnet och sonen får välja musik under festen. - Granddad says that the grandchild and the son may choose the music during the party.

It is capitalized here because it’s being used like a name, similar to English “Grandpa” when you use it as a form of address or as that person’s “name” in the family.

Compare:

Min morfar heter Johan. – My grandfather is called Johan. (common noun, not capitalized)
Morfar säger att … – Grandpa says that … (used like a proper name, capitalized)

Why is there no separate word for “the” before barnbarnet, sonen, and festen?

Swedish usually attaches “the” as an ending on the noun instead of using a separate word like English the.

barnbarn = grandchild
- barnbarnet = the grandchild
son = son
- sonen = the son
fest = party
- festen = the party

So the sentence has three definite forms:

barnbarnet – the grandchild
sonen – the son
festen – the party

That’s why there’s no separate word for “the.”

What exactly does barnbarnet mean, and is it singular or plural?

barnbarnet means “the grandchild” (one grandchild).

Details:

The base word barnbarn literally means “child-child” but is used for grandchild.
barnbarn has the same form for singular and plural in the indefinite:
- ett barnbarn – a grandchild
- (flera) barnbarn – (several) grandchildren
The definite forms show number:
- barnbarnet – the grandchild (singular)
- barnbarnen – the grandchildren (plural)

So barnbarnet in the sentence is one specific grandchild.

Why is the verb får used here instead of something like kan? What does får mean in this sentence?

In this sentence, får is a modal verb meaning “may / is allowed to / gets to”:

får välja ≈ may choose, is allowed to choose, get(s) to choose

Compare:

Morfar säger att barnbarnet och sonen får välja musik.
→ Grandpa says that the grandchild and the son may / are allowed to / get to choose the music.
kan välja would mean “can choose” in the sense of is able to choose / is capable of choosing, which is a different nuance.

So får here is about permission or privilege, not ability.

Why is there no att before välja? In English we say “to choose.”

After modal verbs like få, kunna, vilja, måste, ska, Swedish normally uses the bare infinitive without att.

får välja – may choose / get to choose
kan välja – can choose
vill välja – wants to choose

You do use att with a normal (non‑modal) verb + infinitive:

börjar att välja – begins to choose (though often just börjar välja in modern Swedish)
försöker att välja – tries to choose

So in this sentence, får is a modal verb and takes välja without att.

What does under festen mean, and why is under used instead of something like på?

Here under means “during”, not physically “under/below.”
So:

under festen = during the party

Swedish under often means:

in the course of / during
- under sommaren – during the summer
- under mötet – during the meeting

You could say på festen (literally “at the party”), but there’s a nuance:

under festen emphasizes the time period of the party – throughout / during the event.
på festen emphasizes the location / occasion – at the party (as a place/event).

In this sentence, under festen fits well because we’re talking about which music is chosen during the whole party.

In the clause att barnbarnet och sonen får välja musik, what is the subject and what is the verb?

Inside the att-clause:

Subject: barnbarnet och sonen – the grandchild and the son
Verb: får – may / are allowed to / get to

So the structure is:

att (that) + [subject] barnbarnet och sonen
- [verb] får
  - [infinitive] välja
    - [object] musik

Swedish subordinate clauses (with att) keep Subject–Verb order:

att barnbarnet och sonen får välja musik
not
att får barnbarnet och sonen välja musik ✅ (this would be wrong)

“Barnbarnet och sonen” is plural. Shouldn’t the verb change form? Why is it still just får?

Swedish verbs do not change form for person or number in the present tense.

So:

jag får – I may
du får – you may
han/hon får – he/she may
barnbarnet får – the grandchild may
barnbarnet och sonen får – the grandchild and the son may
vi får – we may
de får – they may

The verb får is the same form for all subjects.
This is true for regular present-tense verbs too:

jag säger, de säger – both are “say” / “am/are saying”

What is the role of the word att in Morfar säger att …?

Here att is a subordinating conjunction meaning “that”, introducing a reported speech / subordinate clause:

Morfar säger att barnbarnet och sonen får välja musik.
= Grandpa says *that the grandchild and the son may choose the music.*

This att is different from att used as an infinitive marker (like English “to”):

att välja – to choose

In your sentence, the att we see is the “that”‑att; the infinitive marker att is not used because får is a modal verb and is followed by the bare infinitive välja.

Why is there no possessive like sin or hans before barnbarnet and sonen? How do we know whose grandchild and son they are?

Swedish often omits possessive pronouns when the owner is obvious from context, especially with close family members.

Morfar säger att barnbarnet och sonen får välja musik.
→ Naturally understood as: Grandpa says that his grandchild and his son get to choose the music.

If you want to be explicit, you could say:

Morfar säger att hans barnbarn och hans son får välja musik.

But that usually sounds unnecessary if it’s clearly Morfar’s family we’re talking about. Context does the job.

Could this sentence also mean that the grandchild and son get to receive music, since få can mean “to get”?

In theory få can mean “to receive” (e.g. få en bok – “get/receive a book”), but in this particular structure “få + infinitive verb” it is almost always interpreted as a modal “may / be allowed to / get to”.

får välja – may choose / get to choose
får sjunga – may sing / get to sing

If you wanted to say “receive music” you’d phrase it differently, e.g.:

får musik i present – (literally) gets music as a present.

So here, the natural and correct reading is permission/privilege to choose, not receiving music.

Why is musik without any article? When would you say musiken instead?

musik is usually treated as an uncountable noun in Swedish, like English “music”.

välja musik – choose music (in general)

You use musiken when you mean “the music” in a specific sense:

Barnbarnet och sonen får välja musiken under festen.
→ The grandchild and the son get to choose the music (the specific playlist / all the tracks) during the party.

In your original sentence, musik is more general – they get to choose what music will be played. Both are possible; musik is more generic, musiken more clearly “the whole music for this party.”