How to use "harder" in a sentence

This was harder than she'd imagined

His eyes were harder, and his smile seemed false

If they can't surprise you, it's harder for them to control you.

The wind was blowing harder, and still she had not come back.

She put her shoulder against it, pushed gently, then harder, and finally the door swung inward.

The flagstone walk that led across her front lawn seemed to be one of those treadmill pathways in a dream, stretching out farther in front of her the harder that she ran, but at last, she reached the end of it and dashed into the street

Elliot shook the machine harder than he had done the last time, then harder still, but it continued to repeat the two-word message in the voice of the country singer, as if an invisible hand were holding the pick-up stylus or laser-disc reader firmly in place.

'So it's the one man we never even thought about!' He went over to the sleeping man and shook him, at first gently, then harder