Nå som lakenet og putevaret er rene, lukter hele soverommet bedre.

Here Nå som means now that.

It introduces a background or reason:

• Nå som lakenet og putevaret er rene = Now that the sheet and the pillowcase are clean

It is not just the word nå meaning now by itself. The combination nå som works as a fixed expression meaning now that / since now.

The ending -et shows that these nouns are:

• singular
• definite
• neuter

So:

• et laken = a sheet
• lakenet = the sheet

and:

• et putevar = a pillowcase
• putevaret = the pillowcase

In the sentence, we are talking about specific bedding items, so the definite form is used.

Because the subject is plural in meaning: lakenet og putevaret = the sheet and the pillowcase.

Even though each noun is singular by itself, together they form a plural subject. Predicate adjectives after er must agree with the whole subject.

So:

• ren = common gender singular
• rent = neuter singular
• rene = plural or definite form

Here we need rene because there are two things:

• lakenet og putevaret er rene = the sheet and the pillowcase are clean

Hele soverommet means the whole bedroom or the entire bedroom.

Breakdown:

• hele = whole / entire
• soverommet = the bedroom

In Norwegian, when hele modifies a specific noun, the noun is usually in the definite form:

• hele huset = the whole house
• hele dagen = the whole day
• hele soverommet = the whole bedroom

So this is the natural way to say that the bedroom as a whole smells better.

This is because Norwegian is a V2 language. In main clauses, the finite verb usually comes in the second position.

The sentence begins with the subordinate clause:

• Nå som lakenet og putevaret er rene

After that comes the main clause:

• lukter hele soverommet bedre

Because the sentence starts with something other than the subject, the verb comes first in the main clause, and the subject comes after it.

Compare:

Normal main clause order:

• Hele soverommet lukter bedre.
• The whole bedroom smells better.

With an opening clause:

• Nå som lakenet og putevaret er rene, lukter hele soverommet bedre.

This inversion is very normal in Norwegian.

Lukter is the present tense of å lukte, which means to smell.

In this sentence it means to give off a smell / to smell like something, not to smell something with your nose.

So:

• Soverommet lukter bedre = The bedroom smells better

Norwegian å lukte can work like English to smell, which also has both meanings:

• Jeg lukter kaffen = I smell the coffee
• Kaffen lukter godt = The coffee smells good

Bedre means better, while godt means good / well depending on context.

This sentence compares the current smell with how it smelled before:

• lukter bedre = smells better

If you said lukter godt, that would mean:

• smells good

So the difference is:

• lukter godt = it smells good
• lukter bedre = it smells better than before

Because the sentence implies improvement after the sheet and pillowcase became clean, bedre is the natural choice.

Because Norwegian usually expresses definiteness by adding an ending to the noun, instead of using a separate article like English the.

Examples:

• the sheet = lakenet
• the pillowcase = putevaret
• the bedroom = soverommet

This is one of the big differences from English. The definite article is often attached to the noun itself.

Yes, lakenet is singular: the sheet.

Norwegian can use the singular where English might sometimes prefer plural, depending on context. Here it refers to one sheet as an item of bedding.

If you wanted plural, it would be:

• lakenene = the sheets

But the sentence as written uses singular:

• lakenet og putevaret = the sheet and the pillowcase

Putevar means pillowcase.

Its indefinite singular is:

• et putevar

Its definite singular is:

• putevaret

So yes, putevaret is the normal definite form.

You may also sometimes see related bedding words such as:

• pute = pillow
• dyne = duvet
• dynetrekk = duvet cover
• sengetøy = bed linen / bedding

Yes, absolutely.

This version is also natural:

• Hele soverommet lukter bedre nå som lakenet og putevaret er rene.

The meaning stays basically the same. The difference is mainly focus and sentence flow.

• Starting with Nå som ... puts the cause/background first.
• Starting with Hele soverommet ... puts the result first.

Both are good Norwegian.

It describes both.

The structure is:

• lakenet og putevaret er rene

Because the two nouns are joined by og (and), rene applies to both of them together.

So the meaning is:

• the sheet and the pillowcase are clean

not:

• the sheet and the pillowcase is clean
• and not just one of them

It often does both at once.

In a sentence like this, Nå som literally points to the present situation, but it also suggests a reason:

• Now that the sheet and pillowcase are clean, the whole bedroom smells better.

So it can feel close to English now that, which often combines:

• a time idea: this is the situation now
• a cause idea: because this is the situation now

That is exactly how it works here.