YOU SAID:
Alligators eat not bird
INTO JAPANESE
ワニは鳥ではなく食べます
BACK INTO ENGLISH
crocodiles eat not birds
INTO JAPANESE
ワニは鳥を食べない
BACK INTO ENGLISH
crocodiles don't eat birds
INTO JAPANESE
ワニは鳥を食べない
BACK INTO ENGLISH
crocodiles don't eat birds
That didn't even make that much sense in English.