Sure! Here are the sentences formed using the prompts given:

1. I like reading comics in my free time. (hobby)
→ Reading comics is my hobby.

2. Tom's favourite hobby is playing online games.
→ Tom likes playing online games as his favourite hobby.

3. Let's have a fun run.
→ How about having a fun run?

4. It's a good idea to organize a talent show to raise money. (should)
→ I think we should organize a talent show to raise money.

5. I don't have any milk in my fridge.
→ There is no milk in my fridge.

6. How about having a craft fair?
→ Let's have a craft fair.

7. What is the price of this cake? (much)
→ How much is the price of this cake?

8. This guitar belongs to him.
→ This is his guitar.