Here are the completed sentences with the appropriate word formations:

1. She has just learnt English for two years. So she speaks English **naturally**.
2. Only a few people know my uncle, an actor because he is **popular**.
3. The children like to be **dependent** on their parents when they grow up.
4. There was little food and no fresh water. They suffered a/an **unhealthy** life.
5. By the time we got to the party, they **had prepared** everything carefully.
6. The student **punished** by Mr. William yesterday is Tom's brother.
7. She felt that she **was being looked at** from her back.
8. You should consider **going** for a picnic at the weekend.

Feel free to ask if you need any more help!