9. speaks
10 costs
11. don't know
12. don't understand // have spoken
b)
1. You are not going there. You should go in the opposite direction.
2. Be careful! The vase is falling!
3. They don't believe me.
4. Boss wants a cup of coffee.
5. No, I'm not sleeping. And what?
6. My neighbour's son often gets in trouble.
7. Look! The cat is catching a mouse!
8. He doesn't often see (meet) his father.
9. I don't remember you.
10. I'm running to the shop.
11. He is translating the text.
12. The professor is reading a lecture on History of England.