every so often

During the night, every so often, the air raid sirens go off.

“We do have a guy who plays with a badly beaten-up fiddle. He comes here every so often. He’s very kind, very gentle and very proper. He’s a delight.”

And yet, every so often, I find myself craving something from that dusty, disrespected corner of the culinary canon.

"I talk to Lee every so often, we are good colleagues and have seen each other at a number of Uefa meetings," he said.

It seems to happen less and less, but every so often, the stars still align.