How would you translate "grit" (personality trait) to Chinese?
毅力 (n)
perserverance; willpower
He has grit = 他有毅力

~

堅毅 (adj)
be strong-willed and perseverant
He is very gritty = 他很堅毅

~

堅毅 (n)
strong will and perserverance
This grittiness = 這份堅毅

Example sentence:

推行革命要有毅力 - Carrying out the revolution requires perseverance (grit)

堅毅的人能衝出困境，走向高峯 - perseverant (gritty) people can break out of  predicament and get to the top

成功全憑民眾的一股毅力/成功全憑民眾的一份堅毅 - Success depends on the perseverance (grittiness) of the people