1. I know how to swim.
2. She knows the answer to the question.
3. They know the city well.
4. We know each other since childhood.
5. He knows how to play the piano.
6. Do you know where the nearest post office is?
7. I know that restaurant, it serves delicious food.
8. They know the rules of the game.
9. She knows all the famous landmarks in the area.
10. We know the professor who teaches that subject.