In the park, people were playing happily.

Smallpox is a disease that caused a lot of suffering in the past.

His words deeply caused me pain.

He missed school because of sickness.

I think his behavior is abnormal.

He spends a lot of time studying.

He reads a lot of books.

My past has made me stronger.

He told the story using the past tense.

Learning how to use past participles is important for understanding English.