useful的比较级是more useful。more useful的意思是更有用的。例句：ActiveScaffold provides a much more useful UI for the model（ActiveScaffold为模型提供了一个更加有用的UI）。

more useful的例句：Knowing this Ithought you'd be more useful to me，but I was wrong（就是了解这点让我觉得你对我大概有更多的帮助，但是我错了）；I think this dictionary is the more useful of the two（我这本字典是两本中更有用的一本）。