If his efforts didn't work, he could just slip away and try something else.

Whether the latest efforts will work, however, is far from clear.

But several efforts to increase its size have not worked as planned.

For a while, my father's efforts at family gun control worked.

How well all these efforts will work remains to be seen.

But American officials are far from sure that the effort will work.

"But it's too early to tell whether those efforts have worked."

To a large extent, that earlier effort has not worked.

Important steps are being taken now, but it will probably take five years or more to know whether the effort is working.

But such efforts have generally not worked in the past.