Maybe I do know a few useful things after all.

Water is one of the most useful things on Earth.

And so I decided it is a useful thing to do.

We need more jobs in which people can do useful things.

I have seen her do many useful things, but never that.

It would be quite a useful thing to know I think.

But if you've got time, and you really want the data gone, then writing more than once is a useful thing to do.

What useful thing could he keep out on the dark lake?

It was a useful thing to have in a house such as this.

That is the most useful thing you can do at this point.