German words ending in -keit

A noun ending in -keit is die, for the same reason -heit is: it is the same suffix.

die Oma the character this deck pins every die-word on

Historically there is one suffix here, not two. -keit is the form -heit takes after adjectives ending in -ig, -lich, -bar and -sam, because the older ending would not sit comfortably against those sounds. möglich gives die Möglichkeit. schwierig gives die Schwierigkeit. tätig gives die Tätigkeit. flüssig gives die Flüssigkeit.

The practical consequence is that there is nothing to decide. The adjective picks the form; you do not. And since both forms are feminine, picking the wrong one leaves you with a vocabulary mistake rather than a gender mistake. Of the two, the vocabulary mistake is far cheaper.

German sometimes slips an -ig in on the way, so the shape is not always visible in the adjective you started from. neu gives die Neuigkeit. geschwind gives die Geschwindigkeit. You could not have predicted which ending those would take, and it does not matter, because the article was never in question.

Read this page and the -heit page as one rule with two spellings. That is what they are.

Worked examples

die Möglichkeit possibility
die Schwierigkeit difficulty
die Geschwindigkeit speed
die Sehenswürdigkeit sight
die Tätigkeit activity
die Wirklichkeit reality

Measured on this deck

100% of the 10 nouns ending in -keit are die

10 nouns in this deck end in -keit and all of them are die, so 100 percent. Add the -heit nouns to that and you have one suffix with a clean record across both of its spellings.

die Sehenswürdigkeit die Sehenswürdigkeiten
die Fähigkeit die Fähigkeiten
die Flüssigkeit die Flüssigkeiten
die Geschwindigkeit die Geschwindigkeiten
die Möglichkeit die Möglichkeiten
die Neuigkeit die Neuigkeiten
die Öffentlichkeit die Öffentlichkeiten
die Schwierigkeit die Schwierigkeiten
die Tätigkeit die Tätigkeiten
die Wirklichkeit die Wirklichkeiten

What a card looks like

Möglichkeit

Try it

The cards below are the general slice and this ending is scarce in it. Any -keit word that does turn up is settled by the -heit page just as well.

Wohnung