1. I think skating is more interesting than mountain-climbing
- S think S V
2. I don't know why my mother is cooking
- S don't/doesn't know wh- S V
3. He collects books whenever he has money
- whenever : bất cứ khi nào
4. How many paintings does she paint?
- Wh- do/does S V?
5. I love flowers so I plant them around my house
- so : nên, đi với mệnh đề