Min søster tørrer hylden af med støvekluden hver fredag.

Because tørre af is a very common Danish verb expression meaning to wipe off / wipe down.

• tørre on its own can mean dry or wipe
• tørre af adds the idea of wiping something clean, often removing dust, water, or dirt

So in this sentence:

• Min søster tørrer hylden af = My sister wipes the shelf off/down

This is similar to English phrasal verbs like wipe off.

Also notice that in a normal main clause, the particle af often comes later in the sentence, after the object:

• tørre hylden af

But in some forms, the two parts can stay together more clearly, for example in an infinitive:

• at tørre hylden af

Because hylden is the definite singular form: the shelf.

Danish usually adds the definite article to the end of the noun instead of putting a separate word in front, as English does.

For hylde:

• en hylde = a shelf
• hylden = the shelf

So:

• Min søster tørrer hylden af = My sister wipes the shelf off

If you said hylde by itself here, it would be ungrammatical. You would need en hylde if you meant a shelf.

For the same reason as hylden: it is the definite singular form.

• en støveklud = a duster / a dust cloth
• støvekluden = the duster / the dust cloth

So med støvekluden means with the duster.

This sentence is talking about a specific dust cloth, not just any one in general.

Because Danish does not usually use both a possessive and the definite ending together in this kind of phrase.

So you say:

• min søster = my sister
• not min søsteren

Compare:

• min bog = my book
• min ven = my friend

The possessive min already makes the noun specific, so the extra definite ending is normally not used.

Because Danish main clauses follow the V2 rule: the finite verb usually comes in second position.

In this sentence:

• Min søster = first element
• tørrer = finite verb in second position

So the structure is:

• Min søster | tørrer | hylden af med støvekluden hver fredag

This also means that if you move another element to the front, the verb still stays second:

• Hver fredag tørrer min søster hylden af med støvekluden.

That is a very important Danish word-order rule.

Here med means with and introduces the tool being used.

• med støvekluden = with the duster

So it tells you what your sister uses to wipe the shelf.

This is very similar to English:

• She wipes the shelf with the duster.

Because hver fredag means every Friday.

• hver = every
• fredag = Friday

In Danish, you usually do not need a preposition here.

So:

• hver fredag = every Friday

Compare:

• hver dag = every day
• hver uge = every week
• hver sommer = every summer

Using på here would not be natural in this sentence.

Tørrer is the present tense form of tørre.

• at tørre = to wipe / to dry
• tørrer = wipes / is wiping

Danish present tense is often made by adding -r to the infinitive.

So:

• jeg tørrer = I wipe
• hun tørrer = she wipes

Unlike English, Danish verbs do not change much depending on the subject. The same present-tense form is used with all persons:

• jeg tørrer
• du tørrer
• hun tørrer
• vi tørrer

A simple way to see it is:

• Min søster = subject
• tørrer = verb
• hylden = direct object
• af = verb particle
• med støvekluden = prepositional phrase
• hver fredag = time expression

So the sentence structure is roughly:

Subject + Verb + Object + Particle + Prepositional phrase + Time

That gives:

Min søster tørrer hylden af med støvekluden hver fredag.

English speakers often notice that af comes after the object. That is normal with this kind of Danish verb-particle construction.

Yes, absolutely.

You can say:

• Hver fredag tørrer min søster hylden af med støvekluden.

This means the same thing, but now the sentence starts with the time expression for emphasis or style.

Notice the word order change:

• when hver fredag comes first, the verb tørrer still stays in second position
• so the subject min søster moves after the verb

That is another example of the Danish V2 rule.

Both hylde and støveklud are common gender nouns.

In Danish, singular nouns are mainly either:

• common gender (en-words)
• neuter (et-words)

For common gender nouns:

• indefinite singular: en
• definite singular ending: usually -en

So:

• en hylde → hylden
• en støveklud → støvekluden

If a noun were neuter, you would often see:

• et in the indefinite
• -et in the definite

For example:

• et bord = a table
• bordet = the table

These words contain sounds that can be difficult for English speakers, especially ø.

A few useful points:

• ø is a rounded front vowel, somewhat like the vowel in French deux or German schön
• tørrer has a soft, quick Danish rhythm and the r affects the vowel sound
• støvekluden begins with the same støv- sound as støv (dust)

Very rough English-style approximations are:

• søster ≈ SUR-ster but with rounded lips on the first vowel
• tørrer ≈ TUR-er but again with rounded lips
• støvekluden ≈ STUR-vuh-kloo-thun as a rough guide only

These are only approximations. The best way to learn them is by listening to native audio and repeating.

Yes. Danish sometimes uses a single verb where English might use a phrasal verb, and sometimes it uses a verb + particle expression like this one.

For cleaning/wiping, these are all possible depending on context:

• tørre af = wipe off / wipe down
• aftørre = a more compact verb with a similar meaning in some contexts

But tørre hylden af is very natural everyday Danish.

For a learner, it is a good idea to memorize tørre af as a fixed expression.