The “simple past” = action that is over and done. Officially called the Preterit Indicative tense.
to eat | comer | ||
I ate | eu com | i | |
you/he/she ate | você/ele/ela com | eu | |
we ate | nós com | emos | |
they/you all ate | eles/elas com | eram | |
(eu) Eu entendi tudo. I understood everything.
(você, ele, ela) Ele nao entendeu. He didn't understand.