Eine v. Einen
Okay how do I know when it is appropriate to use "eine" v "einen". For example "eine Apfel" v. "einen Apfel"? Thanks :-)
'Ein' and 'einen' are only masculine forms. This variation thus occurs only with masculine nouns. When the noun in question is the subject of your phrase, use 'ein'; ex: "Das ist ein Apfel." When the noun is a direct object (receiver of the action), use 'einen.' ex: "Ich esse einen Apfel." This also applies to other articles such as 'dein', 'kein' and 'mein'.
Similarly, eine and einen refer to the gender of the noun. eine would reflect feminine or plural, whereas Einen refers to Masculine. Since you're asking for "einen," it seems as though you're talking of the Accusative case, though eine can be nomanative or accusative (it's the same in both cases).
Therefore, the difference between the two goes back to understanding the vocabulary, such as how it would be the difference bewteen Die Freundin and Der Richter.