Why would a sentence say "Der Mann trinkt" But would say "Die Maus Lernt" I thought "Der" was used as to show possession So why wouldn't the sentence say "Der Maus lernt" Am I wrong or just getting confused with the words that are supposed to show possession????
All the nouns in German have genders. There are three of them: masculine, feminine and neuter, the definite articles being respectively "der", "die" and "das". "Mann" is masculine (fair enough), so it's "der Mann". "Maus" happens to be feminine (note that it has nothing to do with the actual sex of the animal), so it is "die Maus". You may want to review the grammar tips given in the Basic 1 section. I'd also suggest to use a grammar book or to find grammar resources online. Guessing grammar is not very effective.
You may also want to post your questions about German in the German section of Discussions or in any relevant subsection under German.