YOU SAID:

not all fingers are thumbs but all thumbs are fingers

INTO JAPANESE

すべての指が親指ではないが、すべての親指が指である

BACK INTO ENGLISH

All fingers are not thumbs, but all thumbs are fingers

INTO JAPANESE

すべての指は親指ではありませんが、すべての親指は指です

BACK INTO ENGLISH

All fingers are not thumbs, but all thumbs are fingers