I'm / i'm not /
  i was / i wasn't

you're / you're not
you were / you weren't

he's / he isn't
he was / he wasn't

she's / she isn't
she was / she wasn't

it's / it isn't
it was / it wasn't

we're / we aren't
we were / we weren't

you're / you're not /
you were / you weren't

they're / they aren't
  they were / they weren't