YOU SAID:

my uncle eat a tuna while a tuna was eating my uncle

INTO JAPANESE

私の叔父は、マグロが私の叔父を食べている間にマグロを食べる

BACK INTO ENGLISH

My uncle eats tuna while tuna eats my uncle

INTO JAPANESE

私の叔父はマグロを食べ、マグロは私の叔父を食べる

BACK INTO ENGLISH

My uncle eats tuna, tuna eats my uncle

INTO JAPANESE

私の叔父はマグロを食べ、マグロは私の叔父を食べる

BACK INTO ENGLISH

My uncle eats tuna, tuna eats my uncle