So though what I'd been saying meant something to him, he didn't understand the impact of it.

A lot of research needs to be done to understand the long-term impact.

It was hard to understand the impact of this man unless a person saw him for herself.

But do we yet understand the true impact of our actions?

He was coming to understand the impact of his action.

But do we understand the impact of this on America's influence?

I think we have to understand the impact he made on people like my dad in the 60s.

But you have to understand the impact the song has upon me.

Perhaps she did not fully understand the impact of her words.

Costs must be set against savings if we are to understand the full impact.