When to use 'Einen', 'Einem', 'Den' and 'Dem'?
Any help would be appreciated!
"Einen" and "Einem" are the accusative/dative forms of the article "Ein". For example: "Ich backe EINEN Kuchen" - I bake a cake "Ich gebe einem Freund diesen Kuchen" - I give this cake to a friend The same goes for "Den" and "Dem" which are the accusative/dative form of the article "Der". For example: "Ich kaufe DEN Kuchen" - I buy the cake "Ich gebe DEM Bäcker das Geld" - I give the money to the baker
What Somebodystrange (love the name) said; and "einen, einem" is indefinite article ("a", "an") and "den, dem" definite one ("the").
As for the use of the cases, either let Duo guide you, or search for a good grammar site/book. I can explain if you wish, but it will be a looong shot ;)