哪位大侠帮我分析一下下面这句话的语法啊?When times become difficult (and you know they sometimes wil

你这个句子不完整，我刚好回答了一个类似句子，以下是我给那个问题的回答，请参考

When times become difficult (and you know they sometimes will), remember a moment in your life that was filled with joy and happiness.
当日子变得艰难（你也知道有时会这样），要回想起你生命中充满快乐和幸福的时刻。

以上，
When times become difficult 为when引导的时间状语，这个你应该很熟悉吧

(and you know they sometimes will)是插入语，起补充说明作用，类似句子有He was （strange as it seems）an excellent sportsman.

remember a moment in your life/ that was filled with joy and happiness.这句话是祈使句中带了定语从句。我用分隔符 “/” 给你标出了断句。你可以看到remember a moment in your life是简单的祈使句，in your life是后置定语，实际上a moment才是宾语，意为“要回想起你生命中的时刻"（在汉语中也可以发现“时刻”才是宾语），那究竟是什么时刻呢？that was filled with joy and happiness这一长串就来修饰这个“时刻”了，是一个that引导的定语从句。

本来没想到回复，但看到这个句子很好，挺积极向上的~~~想不到一下就打多了~~ 再给你个相似句子自己试试分析？
When life throws you one more obstacle than you think you can handle, remember something you achieved through perseverance and by struggling to the end.

附那个问题的网址：
http://zhidao.baidu.com/question/238438565.html

当日子变得艰难的时候（你知道有时候会……）

这是一个When引导的时间状语从句，作状语。

还有，你给都不是一个完整句子，只能分析这么多啦！

When引导时间状语引导词 times从句中主语 become difficult 从句中谓语，时间转语从句后面应该还有个主句的and you know they sometimes will既然是括号里的 应该是补充说明的部分
希望可以帮到你