Hey I've been using duolingo to start with basic German But I'm still confused with die den der when to use each Also haben and its sisters
die + der + das = definite articles
You need to know that German makes use of different cases to show the relationship of nouns and pronouns to the rest of the sentence.
There are 4 cases in German: Nominativ (nominative), Akkusativ (accusative), Dativ (dative), Genitiv (genitive)
The articles of a word reflect the case. For example, the nominative case of "the dog" is "der Hund". However, the accusative case of "the dog" is "den Hund":
der
nominative: der / accusative: den / dative: dem / genitive: des
die
nominative: die / acussative: die / dative: der / genitve: der
das
nominative: das / accusative: das / dative: dem / genitive: des
I know this must be terribly confusing at first, but you find many posts concerning the case system here: http://germannn.tumblr.com/tagged/case-system
I don't understand your second question. I mean... I don't know what exactly you want me to explain.
haben = to have
It can also be an auxiliary verb in the German perfect tense, but I doubt that you are already that far if you're still at a beginner's level. I also don't know what you mean with "its sisters". Sorry.