YOU SAID:

You can't have the cake and eat it.

INTO JAPANESE

ケーキを食べることはできません。

BACK INTO ENGLISH

You can't eat cake.

INTO JAPANESE

ケーキは食べられない。

BACK INTO ENGLISH

I can't eat cake.

INTO JAPANESE

私は食べられない。

BACK INTO ENGLISH

I can't eat.

INTO JAPANESE

私は食べられない。

BACK INTO ENGLISH

I can't eat.