2 steps:
1 object (lijdende of meewerkende vorm) wordt subject (onderwerp)
2 werkwoord to be + voltooid deelwoord
1 I opened all the windows in the kitchen.
(passive: niet belangrijk wie maar wat er wordt geopend)
All the windows ....
2 werkwoord = opened =
verleden tijd/past simple:
--> to be: were (windows=mv)
--> opened: opened
All the windows were opened in the kitchen by me.