"I do think these data will prove much more useful than what we had in the past."

But, on the other hand, he might prove very useful.

And I had kept them, though without any design of my own, until the moment when they would prove most useful.

This will prove very useful for someone who can't speak!

Perhaps just your knowledge of the Culture would prove useful.

But I've learned other things that will prove useful in time.

The relationship must also have proved very useful to him in the City.

That was quite true, but they were to prove useful now.

Anything else that I thought might prove useful to us.

You'll have to tell these things, for we need to know them, whether they prove useful or not.