1. I have to pay a library fine; I must have (forgot) to return a book on time.

2. Unfortunately, she had already (throw) the map away.
3. My uncle Jack has(drive) a taxicab for over thirty year.
4. Noah had already (write) a letter to his grandfather.

Write correct form of verb in ().

1.forgotten
2thrown
3.drove
4.written

1 answer

1, 2, and 4 are correct.

For 3, use the past participle of "drive."