Jeg skræller en appelsin ved bordet, mens min søster drikker kaffe.

Because Danish verbs do not change according to the subject the way English verbs sometimes do.

In the present tense, skræller is used with all subjects:

• jeg skræller = I peel / I am peeling
• du skræller = you peel / are peeling
• han/hun skræller = he/she peels / is peeling
• vi skræller = we peel / are peeling

So Danish is simpler than English here: you do not need a special ending for I, you, or they.

Danish usually uses the simple present for both:

• a general present action
• an action happening right now

So Jeg skræller en appelsin can mean both I peel an orange and I am peeling an orange, depending on context.

Likewise:

• min søster drikker kaffe = my sister drinks coffee or my sister is drinking coffee

If Danish speakers want to emphasize that something is in progress, they can sometimes use other expressions, but in ordinary sentences the simple present is very common.

Because appelsin is a common gender noun in Danish, so it takes en in the indefinite singular.

Danish has two grammatical genders:

• common gender: takes en
• neuter gender: takes et

So:

• en appelsin = an orange
• appelsinen = the orange

Unfortunately, noun gender often has to be learned word by word.

Because bordet is the definite form: the table.

Compare:

• et bord = a table
• bordet = the table

In Danish, the definite article is usually added to the end of the noun:

• en stol → stolen
• et bord → bordet

So ved bordet means at the table.

Because ved bordet means by/at the table, meaning someone is sitting or standing next to it, usually using it in a normal way.

By contrast:

• ved bordet = at the table / by the table
• på bordet = on the table

So in this sentence, the person is peeling the orange while located at the table, not physically on top of the table.

Because after a possessive like min, Danish normally uses the indefinite form of the noun.

So:

• min søster = my sister
• min bror = my brother
• mit bord = my table

Not:

• min søsteren
• mit bordet

This is different from English, where the noun itself does not visibly change. In Danish, possessives and the suffixed definite ending usually do not appear together in this basic structure.

Because kaffe is being used as an uncountable mass noun here, just like coffee in English.

So:

• drikker kaffe = drinks coffee / is drinking coffee

If you want to specify a particular serving, you could add a word such as:

• en kaffe = a coffee
• en kop kaffe = a cup of coffee

But in this sentence, plain kaffe is the natural choice.

Mens means while and introduces a subordinate clause.

The sentence is made of two parts:

• Jeg skræller en appelsin ved bordet = main clause
• mens min søster drikker kaffe = subordinate clause introduced by mens

It shows that the two actions happen at the same time.

Yes. Mens introduces a subordinate clause, and Danish subordinate clauses follow different word-order rules from main clauses.

In this sentence, you see:

• mens min søster drikker kaffe

That looks similar to English, but the difference becomes clearer when an adverb is added.

Compare:

• Main clause: Min søster drikker ikke kaffe.
• Subordinate clause: ..., mens min søster ikke drikker kaffe.

In a main clause, the finite verb usually comes in the second position.
In a subordinate clause, words like ikke usually come before the finite verb.

So yes, mens matters for word order.

Yes. You can move the subordinate clause to the front:

• Mens min søster drikker kaffe, skræller jeg en appelsin ved bordet.

When a non-subject element comes first in a Danish main clause, the finite verb must still stay in second position. That is why you get:

• ..., skræller jeg ... not
• ..., jeg skræller ...

This is a very important Danish word-order rule.

The letter æ represents a vowel sound that does not exist exactly like this in standard English.

A rough guide:

• æ is somewhat like the vowel in English cat, but you should not rely on that too much.
• skræller is roughly pronounced something like SKREL-er, though the exact Danish sounds are different from English ones.

Also notice the doubled ll, which helps show the preceding vowel is short.

If you want to sound more natural, it is best to listen to native audio and imitate it, because Danish vowels are hard to learn from spelling alone.

The letter ø is another vowel that English does not really have.

A rough approximation:

• sø is somewhat like the vowel in French deux or German schön
• søster is roughly SUR-ster or SER-ster only as a very loose guide, but neither is fully accurate

The important point is that ø is its own sound and should not be pronounced like English o.

As with æ, listening to native pronunciation is the best way to learn it.

Because Danish usually expresses definiteness by adding an ending to the noun instead of using a separate article.

So:

• et bord = a table
• bordet = the table

English uses a separate word, the. Danish often uses a suffix instead.

However, Danish can also use a separate definite word in some other structures, especially with adjectives:

• det store bord = the big table

But in your sentence, bordet by itself is correct.

Most naturally, ved bordet tells you where the speaker is peeling the orange.

So the structure is most naturally understood as:

• Jeg skræller en appelsin ved bordet
• mens min søster drikker kaffe

In practice, it describes the setting of the main action. Context could make it feel like the shared setting for both people, but grammatically it is most closely connected to the main clause.

Yes, absolutely. That would mean something like I am sitting at the table peeling an orange.

The original sentence is perfectly normal, but Danish often uses verbs like sidder, står, or ligger to give a more physical picture of what someone is doing:

• Jeg sidder ved bordet og skræller en appelsin.
• Jeg står ved bordet og skræller en appelsin.

Those versions add extra information about posture or position.

The main clause follows a very common Danish pattern:

• Jeg = subject
• skræller = finite verb
• en appelsin = object
• ved bordet = adverbial phrase of place

Then comes the subordinate clause:

• mens = conjunction
• min søster = subject
• drikker = finite verb
• kaffe = object

So a simplified pattern is:

• Subject + verb + object + place, mens + subject + verb + object

This is a very useful model for building your own Danish sentences.