I mean, what's the actual meaning of it in another way of expression?
Then, その猫を知る者は暗き路地裏をも知る。"The one who knows the cat also knows dark back alleys." would be better.My French to English translation:
"(the one) who" is right
Oh, that is interesting. In other contexts 形が残る could refer to an accessory to a gift or whatnot so I never considered the phrase in a negative light.形が残る refers to the fact that something tangible results from the lesson, papers you can wave around and see how much work is being done. It gives the appearance of study taking place, but they have to be careful not to become complacent, as the total amount of Japanese instruction/exposure is still insufficient.