The difference between the two can be seen by thinking of a child swinging back and forth in the dark.

The light swung back and forth as if someone had just hit it.

It swung back and forth in front of his eyes.

With each conversation, I found myself swinging back and forth.

It swings back and forth by a very small amount.

His feet, which didn't reach the floor, started swinging back and forth.

Its top swung back and forth, as if in search.

The kitchen door was the sort that swings back and forth.

His feet swung back and forth against the front of the love seat.

"It was clear to me that things would swing back and forth," she said.