[误] We need a capable person to help us in time of difficulties.

[正] We need a capable person to help us in times of difficulties.

1、注：time 是指“时间，时候，时刻”

参考例句：Do you have time tomorrow?你明天有时间吗？

2、注：“境况”要用 times

参考例句：What a times you\'ll have doing that  干那事可够你受的

3、hard times(艰难时世)还可表示时代

参考例句：What wonderful times we live in 我们生活在多么了不起的时代啊