"Que" followed by indicative ou subjunctive mood ?

A French learner asked me whether "j'espère que" should be
followed by the indicative ("j'espère que vous gagnerez") or the
subjunctive ("j'espère que vous *gagneriez"). In this case, it's
the indicative but a more general answer would be helpful.

I thought that maybe, if "que" can be translated by "that", the
indicative should be used but how true is that ? Any
counter-examples ?

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>
"Cette supposition rappelle assez celle de ce prédicateur qui, en
pleine chaire, faisait remarquer à ses fidèles la bonté de Dieu qui
avait placé les rivières auprès des villes." -- Alexandre Dumas