Learn Hardcore German: Die Kinder bringen ihre Bücher in die Bibliothek. - The children bring their books to the library.

In German, most neuter and masculine nouns simply take -er or some other plural ending, and the nominative plural article is always “die” (for all genders):

das Kind → die Kinder
der Tisch → die Tische
die Frau → die Frauen

There is no extra -n on Kinder in the nominative plural, so “Die Kindern” is incorrect here.

What case is “ihre Bücher”, and why?

“ihre Bücher” is in the accusative plural, because it is the direct object of the verb bringen (the thing that is being brought).

Verb: bringen (to bring)
- subject (who brings?) → Die Kinder (nominative)
- direct object (what do they bring?) → ihre Bücher (accusative)

In the accusative plural, the noun form Bücher stays the same as in the nominative plural, and there is no special article change for the plural from nominative to accusative:

Nominative plural: die Bücher
Accusative plural: die Bücher

With a possessive like ihr-, the ending -e is used for both nominative and accusative plural:

nominative plural: ihre Bücher
accusative plural: ihre Bücher

So the form “ihre Bücher” works for both cases; here, context tells us it’s accusative.

Why is it “ihre Bücher” and not “ihren Bücher”?

The form of the possessive ihr- must agree with the gender, number, and case of the noun it modifies, not with the owner.

Noun: Bücher
- gender: plural (plural doesn’t have gender in the same way, but grammatically it’s “plural”)
- case: accusative plural
- article in this slot would be: die (accusative plural)

The possessive ihr- takes the same endings as the definite article der/die/das would in that position:

Accusative plural ending: -e → ihre
“ihren” is the ending for masculine accusative singular (like ihren Hund – their dog).

So:

ihre Bücher = their books (accusative plural)
ihren Hund = their dog (accusative singular, masculine)

Since Bücher is plural, you must use ihre, not ihren.

Does “ihre” mean “her” or “their” here?

In German, “ihr” / “ihre” can mean “her”, “their”, or “your” (formal), depending on context and capitalization.

ihr / ihre (lowercase) = her / their
Ihr / Ihre (capitalized) = your (formal “Sie”)

In the sentence “Die Kinder bringen ihre Bücher in die Bibliothek.” the natural reading is:

Subject: Die Kinder (the children)
Possessive: ihre Bücher → their books

So here, “ihre” means “their”, referring back to die Kinder.
It obviously cannot be “her books” (singular) because the subject is plural (the children). And it’s not the formal “your” because Ihr(e) would be capitalized.

Why is it “Bücher” and not just “Buch” for “books”?

Buch is the singular form (“book”), and Bücher is the plural form (“books”). The plural of Buch is irregular:

Singular: das Buch
Plural: die Bücher

Two things change in the plural:

You add -er → Buch → Bücher
You add an Umlaut (¨) to u → u → ü

Many German nouns form their plurals with -er and an Umlaut, especially some neuter nouns:

das Kind → die Kinder
das Buch → die Bücher
das Dorf → die Dörfer

Because the meaning is “books”, you need the plural Bücher.

Why do we say “in die Bibliothek” and not “in der Bibliothek”?

“in” is a two-way preposition in German. It can take dative or accusative:

Dative → location (where something is)
- in der Bibliothek = in the library (location)
Accusative → direction / movement into (where something is going)
- in die Bibliothek = into the library (destination)

In “Die Kinder bringen ihre Bücher in die Bibliothek.” there is movement towards a place (the books are being brought to / into the library), so German uses accusative:

die Bibliothek (nominative) →
in die Bibliothek (accusative, feminine singular)

If the sentence were about location, you’d see the dative:

Die Bücher sind in der Bibliothek. = The books are in the library.

Why is it “die Bibliothek” and not “der Bibliothek” after “in” here?

Because in this sentence “in” shows movement into a place, so it takes the accusative case, not the dative.

Feminine noun: die Bibliothek
- Nominative: die Bibliothek
- Accusative: die Bibliothek
- Dative: der Bibliothek

After “in”:

Movement (into) → accusative: in die Bibliothek
Location (inside) → dative: in der Bibliothek

So “in der Bibliothek” would mean “in the library” (location), which is not the idea of “bringing [something] into the library” here.

Could you also say “zu der Bibliothek” or “zur Bibliothek” instead of “in die Bibliothek”? What is the difference?

Yes, you can say “zu der Bibliothek” (usually contracted to “zur Bibliothek”), but the nuance is different:

in die Bibliothek
- Focus: into the inside of the library
- Implies entering the building / interior.
zu(r) Bibliothek
- Focus: to the vicinity / to that place in a more general sense
- May or may not strongly emphasize entering inside; it’s more like “to the library (as a location).”

In this context, “in die Bibliothek” fits very well because bringing books suggests taking them inside and putting them there. “zur Bibliothek” is understandable but slightly less precise about going into the building.

Why are the nouns “Kinder”, “Bücher”, and “Bibliothek” capitalized?

In German, all nouns are capitalized, regardless of their position in the sentence.

Kinder (children) → noun → capitalized
Bücher (books) → noun → capitalized
Bibliothek (library) → noun → capitalized

This is a standard rule of German orthography and not optional. Verbs, adjectives, and most other words are not capitalized (unless at the start of a sentence or used as nouns).

How is the verb “bringen” conjugated here, and why?

The full infinitive is bringen (to bring). In the sentence:

Subject: Die Kinder → 3rd person plural (“they”)
Verb form: bringen

Conjugation of bringen in the present tense (indicative):

ich bringe
du bringst
er/sie/es bringt
wir bringen
ihr bringt
sie bringen / Sie bringen

For “Die Kinder”, you use the 3rd person plural form bringen:

Die Kinder bringen = The children bring.

So “bringen” is correct because the subject is plural.

Can I change the word order, for example: “Die Kinder bringen in die Bibliothek ihre Bücher”?

Yes, German word order is more flexible than English, especially in the “middle field” (the part between the conjugated verb and the sentence-final verb part, if any). But some orders are more natural than others.

Neutral, most natural:
- Die Kinder bringen ihre Bücher in die Bibliothek.

You can say:

Die Kinder bringen in die Bibliothek ihre Bücher.
- Grammatically possible, but sounds somewhat marked or unusual. It might sound like you are emphasizing the place first and then adding what is brought.

You can also front other elements for emphasis:

Ihre Bücher bringen die Kinder in die Bibliothek.
- Emphasizes “their books” in contrast to something else.

The safest and most natural for learners is the original:

Subject – verb – direct object – prepositional phrase
→ Die Kinder bringen ihre Bücher in die Bibliothek.

How do I know that “Bibliothek” is feminine (so it uses “die”)?

Unfortunately, German noun gender is often not predictable from meaning alone, but there are some patterns and suffix rules.

“Bibliothek” ends in -thek, which is related to the Greek -theke and is typically feminine in German:

die Bibliothek
die Apotheke
die Diskothek

More generally, many nouns ending in -e are feminine (though not all). For vocabulary learning, it’s important to always learn the noun together with its article:

die Bibliothek – the library
das Buch – the book
das Kind – the child

So you memorize “die Bibliothek” as a unit, and that tells you it’s feminine and will use die / der etc. depending on case.