YOU SAID:

if fly fly then bird know no fly but bird yusa fly so fly flee flew

INTO JAPANESE

飛ぶなら、鳥は飛ぶことを知らないが、鳥ユサは飛ぶので飛ぶ

BACK INTO ENGLISH

If you fly, the bird doesn't know to fly, but the bird Yusa flies because it flies

INTO JAPANESE

飛べば鳥は飛ぶことを知らないが、ユサは飛ぶから飛ぶ

BACK INTO ENGLISH

If you fly, you don't know that birds will fly, but Yusa will fly because it will fly

INTO JAPANESE

飛ぶなら、鳥が飛ぶことを知らないが、ユサは飛ぶから飛ぶ

BACK INTO ENGLISH

If you fly, you don't know that a bird will fly, but Yusa will fly because it will fly

INTO JAPANESE

飛ぶなら、鳥が飛ぶことを知らないが、ユサは飛ぶから飛ぶ

BACK INTO ENGLISH

If you fly, you don't know that a bird will fly, but Yusa will fly because it will fly