Interogativ:
1. Do you know my best friend, Lucian?
2. Does she know the lesson?
3. Do they know where we are?
Negativ:
1. I don't know who that person is.
2. Sheila doesn't know where her glasses are.
3. We don't know who is knocking at the door.
Afirmativ:
1. I know English and French well enough.
2. Sarah knows you are not at home.
3. They know this story for a long time.
