Ты не написал пример. Поэтому я не знаю, как именно нужно делать.
Но, что-то в этом роде:
Now i'am eating apple. -- I was eat apple at yesterday.
I'am eating chocolate right now. -- I was eat a chocolate at the last week.
My brother eating a bread with a jam. -- My brother was eat a bread with a jam before this happened.