滴水穿石
Constant dripping wears away the stone.
Feather by feather the goose is plucked.
Slow but sure wins the race.
A sheer strength of will.

eg：Be determined to stick it out as constant dripping wears away the stone.

同义词：持之以恒 Perseverance will prevail.
反义词：三天打鱼，两天晒网 By fits and starts.