Wasser ber das Auto und poliert es. Garten getragen haben. Move on Read through this list of prepositions and case endings used in the article. Learn any that you're not sure about. In German the gender is changed according to the preposition and you are helped by the fact that each preposition demands a specific change.
Different cases change the article according to the gender of the noun.
This table will help you to work out which endings to use. From the list above you can see that mit requires the dative case. If you look up the gender of the word Ball in the dictionary you will find that it is der Ball - masculine. From the table you can see that masculine words change from der to dem in the dative case. Toni spielt mit dem Ball.