That girl is vain of her beauty.
That woman is proud rather than vain.
The drowning man called for help, but in vain.
John tried in vain to solve the problem.
John tried in vain to solve the problem.
I think John is quite selfish, and a little bit vain. He isn't easy to get on with.
All my pains were in vain.
The boy made vain efforts to reach the shore.
The boy tried to move the heavy sofa in vain.
The old lady will often wait for her son in vain at the station.