Core Vocabulary for Deutsch im Blick Kapitel 5:
If you use Quizlets games or tests, you not only have to pay attention to capitalization and plurals, but you further gave to include other information in parentheses (such as past tense forms) as well as proper punctuation.
Otherwise, the system will not count your answer as correct, or you may not be able to proceed.
Plurals, capitalization AND past tense forms are an important part in German. Make it a habit to study it right away. This will save you a lot of headaches later on.