1. My father was **drive** to work when he saw an accident on the road.
→ My father was **driving** to work when he saw an accident on the road.

2. Ngoc was dancing in her room while her brother **were** playing video games.
→ Ngoc was dancing in her room while her brother **was** playing video games.

3. The volunteers made a meaningful **contribute** to the local orphanage.
→ The volunteers made a meaningful **contribution** to the local orphanage.