noun flashcards need definite articles
Repetitive exposure to a noun paired with its definite article causes me to learn gender more effectively than knowing the general gender rules, although the rules are sometimes helpful.
Unless it's a day of the week/month/season or ends in -in, I don't think about the rules much. When I know the gender, I just know it without thinking about it, and that comes from repetitive exposure.
This is a minor quibble - I'm thrilled to see flashcards on duolingo, and I really like the flashcard user interface.
I created two massive English/German Noun study decks in Quizlet, because this request is repeated every five days. The first deck tests your knowledge of the meaning of the noun, and shows you the determiner. The other one shows you the German word and you have to guess the determiner (m,n,f).
As you progress through the deck, create mnemonics for suffix rules:
Masculine Suffix – ant, anz (monosyllable), ar, är, ast, eich, eig, ent, er, eur, ig, ismus, ist, ling, or, ör, us
Feminine Suffix – anz (polysyllable), age, e, ei, enz, esse, euse, heit, ie, ik, ion, in, itis, keit, nis, schaft, sis, tät, tion, ung, ur
Neutral Suffix – a (countries), chen, en, ett, il, in, ing, it, lein, ma, ment, nis, tum, um
Neutral when used as reference – al, an, ar, (m)ent, ett, ier, iv, o, on
As an example, words that end in -ung are feminine, so I think of Connie Chung (American newscaster), while words that end in -ant are masculine (Antman). As you practice this technique and quickly come up with your own mnemonics, the German genders become child’s play. I’ll throw out a few more…these are masculine…Adolph Eichman, Stig (driver on Top Gear), Christ, Ding-a Ling, isthmus = ismus, Thor/Thör, The Bus (American football player) or US (Uncle Sam), ARmy, ER (George Clooney Show), Bar or Bär, Fast (Eddy)
Or maybe this two sentence mnemonic device is all you need for masculines:
Antman, Eichmann, Stig and Christ take a fast bus to a bar. On TV, they see Thor has joined the US Army, and works in the ER in Europe as a linguist.
I wish I knew how to bold the letters, but they are -ant, -eich, -ig, -ist, -ast, -us, -ar, -är, or, -ör, -us, -ar, -er, -eur, -ling...all masculine endings.
For feminine, how about...Chung's sister's kite (keit) action, the dur-a-tion, stät-ur-e and height (heit), had fin-esse.
That covers -ung, -sis, -keit, -ion, -ur, -tion, -tät, -ur, -e, -ei, -heit, and -esse.
Two simple sentences. What percentage of genders can you guess correctly now? Suppose you had a test and wrote those two sentences down, then circled the proper suffices. That certainly takes the pressure off of you during the test, especially if you've reinforced the mnemonic by using it on the flash cards.