-er der
Ordner
Usually 81.3% of the 2,315 common nouns ending in -er take der.
Many -er nouns are masculine, most of all people and machines that do something: der Lehrer, der Computer.
Exceptions die Mutter, die Tochter, die Schwester, das Wasser
der Ordner
It's der Ordner. Ordner is masculine, plural die Ordner.
Die Datei ist im Ordner "Projekte".
The file is in the "Projects" folder.
Ordner
Usually 81.3% of the 2,315 common nouns ending in -er take der.
Many -er nouns are masculine, most of all people and machines that do something: der Lehrer, der Computer.
Exceptions die Mutter, die Tochter, die Schwester, das Wasser