No rule for this one
No ending or word group predicts the article of Korb. Learn it as a pair and say it out loud: der Korb.
der Korb
It's der Korb. Korb is masculine, plural die Körbe.
Ich nehme einen Korb.
I'll take a basket.
No ending or word group predicts the article of Korb. Learn it as a pair and say it out loud: der Korb.