Here are the completed sentences:
- My sister plays the trumpet very badly! (bad)
- Please put the glass on the table carefully! (careful)
- John walked home slowly. His rucksack was very heavy. (slow)
- My dad has a fast car, but he never drives dangerously. (dangerous)
- Marco did his homework quickly. He wanted to watch TV. (quick)
- We have to talk quietly. Grandpa is sleeping. (quiet)
- She was singing very loudly. (loud)
- The dog played happily with a ball in the garden. (happy)