YOU SAID:
The jumpy rock can't cover the activity.
INTO JAPANESE
びくびくした岩は活動をカバーできません。
BACK INTO ENGLISH
Jerky rocks cannot cover the activity.
INTO JAPANESE
ぎくしゃくした岩は活動をカバーできません。
BACK INTO ENGLISH
Jerky rocks cannot cover the activity.
That didn't even make that much sense in English.