YOU SAID:

Jonny doesn't know anything about sharp blades

INTO JAPANESE

ジョニーは鋭い刃について何も知らない

BACK INTO ENGLISH

Johnny knows nothing about sharp blades.

INTO JAPANESE

ジョニーは鋭い刃物について何も知らない。

BACK INTO ENGLISH

Johnny knows nothing about sharp knives.

INTO JAPANESE

ジョニーは鋭いナイフについて何も知らない。

BACK INTO ENGLISH

Johnny knows nothing about sharp knives.