Nominative—Mein guter Freund, my good friend.
Genitive—Meines guten Freundes, of my good friend.
Dative—Meinem guten Freund, to my good friend.
Accusative—Meinen guten Freund, my good friend.
Nominative—Meine guten Freunde, my good friends.
Genitive—Meiner guten Freunde, of my good friends.
Dative—Meinen guten Freunden, to my good friends.
Accusative—Meine guten Freunde, my good friends.
Now let the candidate for the asylum try to memorize those variations, and see how soon he will be elected. One might better go without friends in Germany than to take all this trouble about them. I have shown what a bother it is to decline a good (male) friend; well this is only a third of the work, for there is a variety of new distortions of the adjective to be learned when the object is feminine, and still another when the object is neuter. Now there are more adjectives in this language than there are black cats in Switzerland, and they must all be as elaborately declined as the example above suggested. Difficult? Troublesome? (Mark Twain, ‘The Awful German Language,’ in Twain, 1879, pp. 271–272)