Learn Hardcore Swedish: I affären får vi rabatt om vi köper tre böcker samtidigt. - In the shop we get a discount if we buy three books at the same time.

i affären = in the shop / inside the store
This is the most neutral way to say you are at a shop as a customer.
på affären is possible in some dialects/contexts, but i affären is standard when you’re physically in the store area.
i butiken means exactly the same as i affären;
affär and butik are near-synonyms (both are store / shop), with butik sometimes feeling a bit more formal or “boutique-like”.

So i affären is just the regular, idiomatic way to say in the shop here.

Why do we say affären (definite) and not just affär?

Swedish uses the definite form more than English does when talking about places:

i affären = in the (the) shop → but in English we usually just say in the shop or even in a shop.

In this sentence, we’re talking about a specific store where this discount policy applies, so Swedish prefers the definite form:

affär = a shop (indefinite)
affären = the shop (definite)

Using i affär here would sound wrong; you need the definite form.

What exactly does får mean here? Is it “get” or “may”?

The verb få is very flexible in Swedish. In this sentence, får means:

får rabatt = get a discount / receive a discount

Common meanings of få include:

to get / receive
- Vi får rabatt – We get a discount.
- Jag fick ett paket – I got a package.
to be allowed to / may
- Vi får gå nu – We’re allowed to go now / We may go now.

Context decides which meaning is intended. Here, with rabatt, it clearly means get or receive a discount, not be allowed to discount.

Why is the word order får vi rabatt and not vi får rabatt after I affären?

This is because of the V2 word order rule in Swedish main clauses:

The finite verb (here får) must be in second position in the sentence.
Only one element can come before the verb (subject, time phrase, place phrase, etc.).

Your sentence starts with a place phrase:

I affären (1st element)
får (finite verb, must be 2nd)
vi (subject)
rabatt (object)
om vi köper tre böcker samtidigt (subordinate clause)

So:

I affären får vi rabatt … ✅ (V2 respected)
I affären vi får rabatt … ❌ (verb is not in 2nd position)

If you start with the subject instead, you say:

Vi får rabatt i affären om vi köper tre böcker samtidigt.

Does rabatt mean “sale”, “offer”, or specifically “discount”?

Rabatt is specifically discount / price reduction.

få rabatt – get a discount
10 % rabatt – 10% off

It does not automatically mean “special offer” as in buy 2, get 1 free (even if such an offer often involves a discount).

Other terms:

erbjudande – offer, special
rea – sale (period with reduced prices, like a clearance sale)
kampanj – promotion / promotional offer

Why is it om and not när in om vi köper tre böcker?

om and när both translate to if/when, but they’re used differently:

om = if (condition / possibility)
- Vi får rabatt om vi köper tre böcker.
  We get a discount if we buy three books. (conditional)
när = when (time; something you expect will happen or always happens)
- Vi får rabatt när vi köper tre böcker.
  Can mean: Whenever we buy three books, we get a discount (general rule), or When we buy three books (and we will), we get a discount.

In this sentence, om stresses it as a condition: the discount only applies if you fulfill it.

Is it correct to drop the second vi and say … om köper tre böcker samtidigt?

No. In Swedish, you can’t normally drop the subject pronoun like that.

Each clause needs its own subject:

om vi köper tre böcker samtidigt ✅
om köper tre böcker samtidigt ❌ (subject missing)

Swedish is not a “pro-drop” language like Spanish or Italian, so you generally must state the subject (like English does).

Why is the verb köper (present tense) and not köpa?

In the clause om vi köper tre böcker samtidigt:

om introduces a full clause with its own subject (vi) and finite verb (köper).
So you need the present tense form köper, not the infinitive köpa.

Compare:

Jag vill köpa tre böcker. – I want to buy three books.
→ after vill, you use the infinitive köpa.
Om jag köper tre böcker, får jag rabatt. – If I buy three books, I get a discount.
→ köper is the main verb of the om-clause, so it must be finite (present).

Why is the plural böcker and not bokar or böker?

Bok is an irregular noun in Swedish. Its forms are:

en bok – a book (singular, indefinite)
boken – the book (singular, definite)
böcker – books (plural, indefinite)
böckerna – the books (plural, definite)

Notice two things in böcker:

Vowel change: o → ö
The plural ending -er

Many common Swedish nouns change the vowel in the plural (strong nouns), e.g.:

en hand → händer – hand → hands
en tand → tänder – tooth → teeth

So tre böcker is the correct irregular plural.

What does samtidigt add here? Could I just say tre böcker?

samtidigt means at the same time / simultaneously.

tre böcker – just three books
tre böcker samtidigt – three books at the same time (in one purchase / in one go)

The word samtidigt clarifies that:

The discount applies when you buy all three in the same transaction, not just eventually, over time.

Without samtidigt, it could sound a bit less explicit about needing to buy them together, though context would still suggest it.

Can samtidigt go somewhere else in the sentence?

Yes, adverbs like samtidigt are fairly flexible, though some positions sound more natural.

Your version:

… om vi köper tre böcker samtidigt. ✅ (very natural)

Other possible (but slightly different-sounding) positions:

… om vi samtidigt köper tre böcker.
→ emphasizes samtidigt a bit more.
Samtidigt får vi rabatt i affären om vi köper tre böcker.
→ now samtidigt modifies får (at the same time we get a discount…), not clearly the buying of three books.

So the original placement (tre böcker samtidigt) clearly links the “at the same time” to the buying of three books, which is what we want.

Why is there no comma before om in Swedish, when in English we might use a comma before if?

Swedish comma rules are stricter than English ones in this area:

When a subordinate clause (like om vi köper tre böcker samtidigt) comes after the main clause, Swedish usually does not use a comma:
- Vi får rabatt om vi köper tre böcker samtidigt. ✅
- Vi får rabatt, om vi köper tre böcker samtidigt. ❌ (not standard)
If the subordinate clause comes first, you do often use a comma:
- Om vi köper tre böcker samtidigt, får vi rabatt.

So the sentence as given follows normal Swedish comma usage.