The accusative case is used to indicate direct objects, but also includes objects of prepositions such as durch, für, gegen, ohne, and um. Direct objects are those being “verbed” by the subject, for example:
The boy sees the book. (Subject – Verb – Direct Object)
The subject of the sentence (the one performing the action/verb) is the boy. The direct object is the one being “verbed,” in this case, “seen.” Thus, the book is the direct object. Please note that not all verbs take direct objects — those that do are labeled “transitive” and those that do not are “intransitive.” An example of an intransitive verb is “to go”: one can go somewhere (part of a prepositional phrase, e.g. to the store, to Europe), but the place is not “being gone” (i.e. it makes no sense to think of a fixed location moving to another place).
There is very little change from the Nominative to the Accusative cases: only masculine nouns and their articles are affected. The definite article der and the indefinite and negative articles ein and kein change to den, einen, and keinen, respectively. Take a look at the table below:
Examples: Ich möchte den/einen/keinen Apfel.
Du isst die/eine/keine Birne.
Er hört das/ein/kein Auto.
Wir sehen die/—/keine Eltern.
The personal pronouns also change to some extent in the accusative case:
In addition to the articles and pronouns, there are 5 commonly used prepositions that always take the accusative case, as well as 9 that can be used with either the accusative or dative cases, depending on the context. They are:
Akkusativpräpositionen (always accusative)
Wechselpräpositionen im Akkusativ (two-way prepositions in the accusative)
*Typically, “zwischen” is used with two or more objects (e.g. Er geht zwischen den Park und die Kirche.).
Two-way prepositions are often used in conjunction with a handful of verbs of location:
stellen – to place (upright) stehen – to be upright/stand
setzen – to set (oneself) sitzen – to sit
legen – to lay (down) liegen – to lie
stecken – to place/stick inside stecken – to be inside
hängen – to hang (something) hängen – to be hanging on something
These verbs of location take accusative when a subject is placing an object somewhere (e.g. Das Mädchen legt das Buch auf den Tisch. / The girl lays the book on the table.), whereas the dative case is used to describe a fixed or static location (e.g. Das Buch liegt auf dem Tisch. / The book lies/is lying on the table.).