In the park, people were playing happily.

Once upon a time, there was a big castle in this place.

Once, we used to play in the park every day.

In the past, we used to play in the park every day.

He tends to hold onto past failures.

As dawn broke, I could hear the birds singing.

He always wakes up early.

I plan to go to sleep early tonight.

As soon as he gets home, he immediately falls asleep.

It's already too early, I can't do anything.