Min rygsæk er fyldt med bøger og papirer.

Because rygsæk is a common-gender noun in Danish, not a neuter noun.

Danish possessives agree with the gender and number of the noun:

• min = for a common-gender singular noun
• mit = for a neuter singular noun
• mine = for plural nouns

So:

• min rygsæk = my backpack
• but mit hus = my house
• and mine bøger = my books

Literally, ryg means back, and sæk means sack or bag. So rygsæk is basically back-sack, which corresponds to backpack in English.

This is a very typical Danish compound noun: two nouns joined into one word.

This is the normal Danish word order for a simple statement:

subject + verb + complement

So:

• Min rygsæk = subject
• er = verb
• fyldt med bøger og papirer = complement

It works very much like English:

• My backpack is filled with books and papers.

Nothing unusual is happening here.

In this sentence, fyldt functions like an adjective, meaning filled.

The structure er fyldt med means is filled with.

Grammatically, fyldt comes from the verb at fylde (to fill), but in sentences like this it is often best understood as an adjective describing the backpack’s state.

So:

• Rygsækken er fyldt. = The backpack is full / filled.
• Glasset er fyldt med vand. = The glass is filled with water.

Yes, absolutely. That is very natural too.

There is a small nuance:

• fyldt med = filled with
• fuld af = full of

Both are common and correct.

So these are both fine:

• Min rygsæk er fyldt med bøger og papirer.
• Min rygsæk er fuld af bøger og papirer.

The first can sound a little more like filled with, while the second is the more direct equivalent of full of.

Because med means with, and the expression is fyldt med = filled with.

This is the standard preposition used after fyldt in this meaning.

Examples:

• Kassen er fyldt med tøj. = The box is filled with clothes.
• Værelset er fyldt med mennesker. = The room is filled with people.

So med is just the natural preposition required by this expression.

Because the sentence is talking about books and papers in general, not one single book or one single paper.

The singular forms are:

• bog = book
• papir = paper / a paper

The plural forms are:

• bøger = books
• papirer = papers / documents

Notice that bog changes vowel in the plural:

• bog → bøger

That kind of vowel change is common in Danish.

Because Danish often uses a bare plural when speaking generally, just like English can.

So:

• med bøger og papirer = with books and papers

You do not need nogle here.

If you added nogle, it would mean something more like some:

• med nogle bøger og papirer = with some books and papers

That is possible, but the original sentence sounds more neutral and natural.

Yes, very close. Papirer can mean:

• papers
• documents
• loose sheets of paper, depending on context

In this sentence, it most likely means loose papers or documents inside the backpack.

So bøger og papirer is a very natural combination, like books and papers in English.

A rough English-friendly guide would be something like roog-sek, but that is only approximate.

A few important points:

• ryg has a vowel sound that does not exist in standard English
• sæk has a vowel somewhat like the a in cat, but not exactly
• the g in ryg is not pronounced like a hard English g in go

If you are learning pronunciation, it is best to listen to native audio for:

• ryg
• sæk
• rygsæk

Compound words in Danish are usually stressed on the first part, so the main stress is on ryg.

Yes. Og simply means and.

So:

• bøger og papirer = books and papers

It is the normal coordinating conjunction used to join nouns, adjectives, clauses, and so on.

Not in normal standard Danish. The usual and correct way is:

• min rygsæk

Danish possessives normally come before the noun in this kind of sentence.

You may sometimes see other possessive patterns in poetry, dialect, or special expressions, but for ordinary modern Danish, min rygsæk is what learners should use.

The indefinite singular is:

• en rygsæk = a backpack

The definite singular is:

• rygsækken = the backpack

So you could also say:

• Rygsækken er fyldt med bøger og papirer. = The backpack is filled with books and papers.

This is a good example of how Danish usually adds the definite article to the end of the noun:

• en rygsæk → rygsækken

Yes, it is completely natural and correct.

A native speaker would easily say:

• Min rygsæk er fyldt med bøger og papirer.

A slightly more conversational alternative might be:

• Min rygsæk er fuld af bøger og papirer.

But the original sentence sounds perfectly normal and idiomatic.