Soppkniven og soppbørsten brukes i skogen.

Because -en is the usual definite singular ending for many common-gender nouns in Bokmål.

• en kniv = a knife
• kniven = the knife
• en børste = a brush
• børsten = the brush

So:

• soppkniven = the mushroom knife
• soppbørsten = the mushroom brush

In Norwegian, the definite article is often attached to the end of the noun instead of being a separate word like English the.

Norwegian usually forms compound nouns as one single word.

So:

• sopp
  • kniv → soppkniv
• sopp
  • børste → soppbørste

This is very normal in Norwegian. English often writes similar expressions as two words, but Norwegian usually joins them.

A helpful rule is: the last part is the main noun, and the earlier part describes it.

• soppkniv = a kind of knife
• soppbørste = a kind of brush

Brukes is the -s passive form of bruke.

• bruker = uses / are using
• brukes = is used / are used

So:

• Soppkniven og soppbørsten brukes i skogen
  = The mushroom knife and the mushroom brush are used in the forest

This is a very common way in Norwegian to make general statements about how something is used.

You can often compare:

• Den brukes = It is used
• De brukes = They are used

Even though English uses are used, Norwegian can express this neatly with -s.

In this sentence, learners should understand it as a passive meaning: are used.

Norwegian -s forms can sometimes overlap with what is called middle voice in grammar explanations, but here the simplest and most useful interpretation is:

• brukes = is used / are used

A very close alternative would be:

• Soppkniven og soppbørsten blir brukt i skogen

That also means The mushroom knife and the mushroom brush are used in the forest.

Very roughly:

• brukes often sounds compact and general
• blir brukt can sound a bit more explicit as a passive

I skogen literally means in the forest / in the woods.

Norwegian often uses the definite form in places where English might use a more general expression. So i skogen is a very natural way to say out in the forest/woods.

Compare:

• i en skog = in a forest
  one forest, not previously known or not specific
• i skogen = in the forest / in the woods
  the normal, natural place people have in mind

In everyday Norwegian, i skogen is the usual phrasing here.

Because i commonly means in for being inside or within an area.

So:

• i skogen = in the forest

That is the normal preposition here. English and Norwegian match quite well in this case.

Some learners wonder about på, but på skogen is not the standard choice for this meaning in normal Bokmål. I skogen is the natural phrase.

Because Norwegian usually expresses the by adding a definite ending to the noun itself.

So instead of saying something like the mushroom knife, Norwegian says:

• soppkniven

And instead of the mushroom brush:

• soppbørsten

This is one of the biggest structural differences from English.

English:

• the knife

Norwegian:

• kniven

The the idea is built into the noun ending.

Yes, it matters. In compounds, the last element determines the gender and inflection.

• kniv is usually common gender in Bokmål: en kniv, kniven
• børste is also usually common gender: en børste, børsten

So the compounds follow the same pattern:

• en soppkniv → soppkniven
• en soppbørste → soppbørsten

The first part, sopp-, does not decide the gender. The final noun does.

In modern Norwegian, verbs usually do not change according to the subject the way they do in English.

English:

• it is used
• they are used

Norwegian:

• den brukes
• de brukes

The verb form stays the same.

So even though the subject is two things joined by og (and), the verb is still just brukes.

It can feel a bit general even though the nouns are definite.

That is quite normal in Norwegian. The sentence can be understood as a general statement about these tools:

• The mushroom knife and the mushroom brush are used in the forest
• more naturally in English: A mushroom knife and a mushroom brush are used in the forest, or Mushroom knives and brushes are used in the forest, depending on context

Norwegian often uses the definite form in ways that do not match English word-for-word. So the sentence may refer to:

• a specific known knife and brush, or
• the typical tools used for mushroom picking

Context decides.

The word order is:

• Soppkniven og soppbørsten = subject
• brukes = verb
• i skogen = place expression

So the sentence follows a basic Norwegian main-clause pattern:

subject + verb + adverbial

This is very similar to normal English word order here:

• The mushroom knife and the mushroom brush
  • are used
    • in the forest

A natural active version would be:

• Man bruker soppkniven og soppbørsten i skogen.

Literally:

• One uses the mushroom knife and the mushroom brush in the forest.

More natural English:

• People use the mushroom knife and the mushroom brush in the forest.

Here:

• man = an impersonal one/people
• bruker = use

Norwegian often switches between:

• passive: Soppkniven og soppbørsten brukes i skogen
• active with man: Man bruker soppkniven og soppbørsten i skogen

Both are common.