Learn Hardcore Icelandic: Hún lagar bilaðan bíl heima.

Both are possible in Icelandic present tense. Context decides. If you want to make the ongoing action explicit, you can say: Hún er að laga bilaðan bíl heima (She is fixing a broken car at home).

Why is it bíl and not bíll?

Bíl is the accusative singular of the masculine noun bíll (car). The direct object of a verb like laga is in the accusative:

nominative: bíll
accusative: bíl
dative: bíl
genitive: bíls

Why does the adjective say bilaðan with -an?

Adjectives agree with the noun in gender, number, and case. Here the noun bíl is masculine, singular, accusative, and indefinite. With an indefinite noun, you use the strong adjective endings. Masculine accusative singular strong ending is typically -an, hence bilaðan bíl.

How would I say “the broken car”?

With a definite noun, Icelandic uses the suffixed article and weak adjective endings:

the car: bílinn
the broken car: bilaða bílinn Full sentence: Hún lagar bilaða bílinn heima.

Can I leave out the adjective and just say Hún lagar bíl heima?

Yes, it’s grammatical: Hún lagar bíl heima (She fixes a car at home). Including bilaðan just adds the detail “broken.”

What’s the difference between bilaður and brotinn?

bilaður = broken down, out of order (mechanical/electronic failure). Very natural for cars and machines.
brotinn = physically broken (snapped, shattered). For a car that won’t run, bilaður bíll is the normal choice.

How is “heima” used here? Why no preposition like “at”?

Heima is an adverb meaning “at home,” so no preposition is needed. Contrast with heim, which is directional (“homeward, to home”): Hún fer heim (She goes home) vs Hún er heima (She is at home).

Can I say “at her own home” more explicitly?

Yes:

heima hjá sér = at her own home
heima hjá henni = at her (someone else’s) home So: Hún lagar bilaðan bíl heima hjá sér.

Where can I put heima in the sentence?

Default is after the object: Hún lagar bilaðan bíl heima. You can front it for emphasis; Icelandic keeps the finite verb in second position:

Heima lagar hún bilaðan bíl. Putting it between verb and object is possible but less neutral: Hún lagar heima bilaðan bíl.

How do I negate the sentence?

Place ekki after the finite verb:

Hún lagar ekki bilaðan bíl heima. (She does not fix a broken car at home.)

How do I say it in the past or future?

Past: Hún lagaði bilaðan bíl heima. (She fixed…)
Future (with munu): Hún mun laga bilaðan bíl heima. (She will fix…)

What if it’s plural: “broken cars”?

Indefinite accusative plural: bilaða bíla Full sentence: Hún lagar bilaða bíla heima.
Definite: biluðu bílana (weak adjective with definite noun): Hún lagar biluðu bílana heima.

Why is the adjective before the noun, like in English?

That’s the normal position in Icelandic: bilaðan bíl (broken car). Post-nominal adjectives exist but are limited and often carry a special or emphatic meaning; not needed here.

Is there any other common verb for “repair” besides laga?

Yes, gera við is very common for physical repairs:

Hún gerir við bilaðan bíl heima. Both laga and gera við are natural here.

What’s the dictionary form of bilaðan?

The base (masculine nominative singular) is bilaður. You’ll also see:

feminine nom. sg.: biluð
neuter nom. sg.: bilað Accusative masculine singular (strong): bilaðan.

How do I pronounce the sentence?

Approximate guide (IPA-ish, simplified):

Hún [huːn] (ú is a long [uː])
lagar [laːɣar] (g between vowels is a voiced fricative [ɣ])
bilaðan [ˈpɪːlaˌðaːn] (b at word start often sounds like [p]; ð as in English “this”)
bíl [piːl] (í is [iː])
heima [ˈheiːma] (ei ≈ English “ay” in “say”) Put together smoothly: [huːn ˈlaːɣar ˈpɪːlaˌðaːn piːl ˈheiːma].