His hands become still for a moment and he frowns hard.

She frowned harder, but also got the point that I didn't want to talk.

He frowned harder, came around the desk, and closed the door.

A small grin still drew at his mouth, but he was frowning hard.

Mwahu frowned hard at her, then continued to lead them on.

He frowned hard while my heart thumped half a dozen times.

"I have," said Paul, frowning hard, trying to remember the least detail.

Eric glanced up at Roland, and both men frowned hard.

He frowned harder, then arched his eyebrows and looked up at me.

He frowns hard at me, as if he can't believe this.