The 4 cases and articles

Articles

Dieser
The german equivalent for "this" or "these"

Other than articles and possessive determiners, there are other “little words” that often come in front of German nouns with different endings/forms than articles. You will have to remember these.
They follow the same pattern as dieser.

• alle (all)

• beide (both)

• einige (some)

• jeder (each, every)

• jener (that)

• mancher (some, many)

• mehrere (several)

• solcher (such)

• viele (much, many)

• welcher (which)

• wenige (few)
  
  

Prepositions that indicate location/direction and can be paired with either dative or accusative
To decide if to use dative or accusative, remember this simple rule:

*** If you’re talking about direction, use the accusative.
(ex: Ich gehe in die Stadt. I go to town.
This means you are moving and answers the question "Wohin? Where?")

*** If you’re talking about location/position, use the dative. (ex: Ich bin in der Stadt. I am in town. In this case, you are not moving so it answers the question "Wo bist Du? Where are you?")

• an – on

• auf – on

• hinter – behind

• in – in

• neben – beside

• über – over, above, about

• unter – under

• vor – in front of, before

• zwischen – between, among
  
  

Examples

Preposition + article

bei + dem = beim - at the
zu + dem = zum - to the
zu + der = zur - to the
von + dem = vom - from the
in + dem = im - in the
an + dem = am - at the/on the
in + das = ins - into the
an + das = ans - on the/to the
auf + das = aufs - on the

Genitive

Genitive - expresses possesion, relationship or origins

Examples:
Das Buch des Mannes - the man's book
In this example, the book is the man's possesion.

Genitive prepositions:

• (an)statt – instead of

• trotz – despite, in spite of

• während – during (refering to time)

• wegen – because of

Accusative

Akkusativ - represents the direct object, the receiver of the action

Akkusativ - Wohin?
in + das - ins
an + das - ans

Accusative prepositions:

• bis – as far as, by, until

• durch – through, across

• für – for

• gegen – against

• ohne – without

• um – around, about, at

How to use them correctly

Nouns cand be can combined with possessive articles like mein (my), dein (your), sein (his/its) etc.
These possessive articles change depending on gender of the noun or if is singular/plural, as you can see in the table above: masculine and neuter have no ending while feminine and plural have an -e added.

Examples:
Sie gibt mir ihre Nummer. - She gives me her number. (die Nummer - feminine, singular)
Das ist seine Frau. - That's his wife. (die Frau - feminine)
Das ist dein Mann. - That's your husband. (der Mann - masculine)
Das sind unsere Kinder. - Those are our children. (Kinder - plural)

Possessive articles (mein/dein/sein/unser ...)

bis
durch
ohne
gegen

um
für

Akkusativ

WOHIN...?

Dativ

WO...?

an
von
über
unter
zwischen

in
auf
neben
hinter

bei
mit
von
seit

ab
nach
aus
zu

außer
gegenüber

• Nominativ (nominative) - the subject, who or what is performing the action?

• Genitiv (genitive) - expresses possesion, relationship or origins

• Dativ (dative) - represents indirect object, to or for whom is the action performed

• Akkusativ (accusative) - represents the direct object, the receiver of the action

Conclusions:
Dativ: Wo? (Where?) when you’re talking about the location/position
Akkusativ: Wohin? (where to?) - when referring to direction/movement

Examples:
Öffne diese Tür. - Open this door. (die Tür)
Ich mag dieses Lied. - I like this song. (das Lied)
In dieser Stadt ist viel los. - There's lots to do in this city. (die Stadt)
Dieser Eimer leckt. - This bucket leaks. (der Eimer)