Sara vill fotografera barnen vid sjön innan solen går ner.

Because vill is a modal verb. In Swedish, modal verbs such as vilja, kunna, måste, ska, and får are normally followed directly by the infinitive.

So you say:

Sara vill fotografera ...

not:

Sara vill att fotografera ...

Here, fotografera stays in the infinitive because it depends on vill.

Fotografera is the infinitive form of the verb, equivalent to to photograph.

A few forms are:

• att fotografera = to photograph
• fotograferar = photographs / is photographing
• fotograferade = photographed
• fotograferat = photographed

After vill, Swedish uses the infinitive, so vill fotografera = wants to photograph.

Barnen is the definite plural form: the children.

The noun barn is a little unusual because the indefinite singular and indefinite plural look the same:

• ett barn = a child
• barn = children
• barnet = the child
• barnen = the children

So barnen tells you that these are specific children, not just children in general.

Because vid means by, beside, or at.

So:

• vid sjön = by the lake / at the lake
• i sjön = in the lake
• på sjön = on the lake, out on the water

If Sara wants to photograph the children at the lakeside, vid sjön is the natural choice.

Sjö is an en-word: en sjö = a lake.

To make many common-gender nouns definite singular, Swedish adds -n if the noun already ends in a vowel:

• en sjö = a lake
• sjön = the lake

This is the same pattern as:

• en ö → ön
• en sko → skon

So sjön simply means the lake.

Because Swedish often uses the definite form for things that are understood as specific or unique in the situation.

So:

• solen = the sun
• månen = the moon
• himlen = the sky

In this sentence, it is the specific sun everyone knows about, so solen is the natural form.

Because innan introduces a subordinate clause.

In a Swedish main clause, the finite verb usually comes in second position. But in a subordinate clause, the subject normally comes before the finite verb.

So:

• main clause pattern: Solen går ner
• subordinate clause after innan: innan solen går ner

That is why solen comes before går here.

It is a verb plus a particle: gå ner.

This kind of combination is very common in Swedish. The particle changes the meaning of the basic verb.

• gå = go / walk
• gå ner = go down

With solen, går ner means sets or literally goes down.

In the sentence, the finite verb is går, and the particle ner stays after it:

solen går ner

Yes. Ner and ned are closely related forms, and both can be correct.

In modern everyday Swedish, ner is usually more common, especially in speech. So solen går ner sounds very natural.

You may still see ned in writing, and some speakers use it more than others.

Because Swedish often uses the present tense for future events when the time is already clear from the context.

After time words and conjunctions like innan, när, and efter att, this is very common.

So:

innan solen går ner

literally uses present tense, but it means before the sun goes down in the future.

English does something similar in time clauses:

• before the sun goes down
• not usually before the sun will go down

Yes, fotografera is perfectly natural.

A very common everyday alternative is ta kort på:

• Sara vill fotografera barnen
• Sara vill ta kort på barnen

Both work. Fotografera sounds a bit more neutral or slightly more formal, while ta kort på is very common in casual speech.

Usually, people will understand it as the location of the photographing: Sara wants to photograph the children by the lake.

But structurally, there is a slight ambiguity, just as in English with the children by the lake.

If you want to make it clearer, you could rephrase:

• Sara vill fotografera barnen när de är vid sjön = Sara wants to photograph the children when they are by the lake.
• Sara vill fotografera barnen där, vid sjön = Sara wants to photograph the children there, by the lake.

In normal use, though, the original sentence sounds natural and clear enough.

The sj sound is one of the hardest Swedish sounds for English speakers. It does not have an exact English equivalent.

In sjön, the beginning is not a simple English sh sound, although that is often the closest beginner approximation. The real Swedish sound is usually produced farther back in the mouth.

So for a learner:

• a rough beginner approximation: shön
• more accurate Swedish pronunciation: a special Swedish sj sound + ö

If you say something close to shurn or shern with rounded lips, people will often still understand you, but native pronunciation is trickier than that.