"The horses run on the second day."
Translation:Am zweiten Tag laufen die Pferde.
A good rule is also to remember what prepositions go with dative. They are: bei, mit, seit, aus, zu, nach, von So if you have them in the sentence, the following noun is in dative. Also there are two-way prepositions that are used with both accusative and dative, they are: hinter, an, neben, auf, unter, zwischen, vor, in, über If the two-way preposition indicates action, it is accusative and if it indicates position it is dative