Then he realized the futility of his efforts and stepped back.

I start to mention this, but realize the futility of it.

He half rose as if to help him, then realized the futility of it and sank back.

In a moment, though, he realized the futility and changed his mind.

There were other days when 1 realized the futility of my search.

But her marriage should have made him realize the futility of his wish.

The Shadow, who realized the futility of such an effort, shook his head.

In that instant, she realized the futility of further combat.

I started to protest, realized the futility, kept my mouth shut.

He tried to apologize but soon realized the futility of it.