sit -> сидеть
Образование времен: Субъект подвергается (Пассив, или иначе страдательный залог)
  Past - ПрошлоеPresent - НастоящееFuture - Будущее
Факт - Simple
I/he/she/itwe/you/they
was satwere sat
---
was not satwere not sat
wasn't satweren't sat
Ihe/she/itwe/you/they
am satis satare sat
---
am not satis not satare not sat
 isn't satare'nt sat
I/he/she/it/we/you/they
will be sat
---
will not be sat
won't be sat
Процесс - Continuous
I/he/she/itwe/you/they
was being satwere being sat
---
was not being satwere not being sat
wasn't being satweren't being sat
Ihe/she/itwe/you/they
am being satis being satare being sat
---
am not being satis not being satare not being sat
 isn't being satare'nt being sat
Завершенность - Perfect
I/he/she/it/we/you/they
had been sat
---
had not been sat
hadn't been sat
I/we/you/theyhe/she/it
have sathas sat
---
have not sathas not sat
haven't sathasn't sat
I/he/she/it/we/you/they
will have been sat
---
will not have been sat
won't have been sat
Вместо отсутствующих форм Perfect Continuous употребляются формы Perfect
sit -> сидеть