It's difficult to make sentences using infinitives.

The calculation of an indefinite integral can be considered as the reverse operation of differentiation.

His attendance is irregular.

His irregular attendance is disrupting the team's schedule.

He lost everything.

She is planning a date with her current boyfriend.

My boyfriend gave me a gift.

Everyone was surprised by the news.

The depressed cowry lives quietly at the bottom of the sea.

He likes to take a walk in the park at dusk.