我们现在对国际事务感兴趣。
[误] We are interested in world affair now.
[正] We are interested in world affairs now.
注:affair 指与公众有关的“事务”时,须用复数形式,所以误句中的world affair 须改为world affairs。另外, current affairs(时事),foreign affairs(外交事务),affairs of state(国是)等,也都用复数形式。在指“(关系到某个人的事)时,用单数。在指某一事件时,用单数,在 have an affair with sb.(与某人私通)这个固定词组中用单数。