Please, I don't understand what I have to do.

我的确不明白我该做什么。

《牛津词典》

You begin to understand what actions were the mainspring of the story.

你开始明白什么是这个故事的主要情节了。

《柯林斯英汉双解大词典》

I don't understand what he's saying.

我不明白他在说些什么。

《牛津词典》

Yet another sign is struggling to find the right words to express thoughts or understand what is being discussed.

VOA: special.2009.09.15

Their argument is that it's not just that consciousness doesn't clearly understand what it's looking at and is therefore alienated from it.

他们的论点是,意识不仅无法清楚地理解它所观之物,因而与之疏远。

耶鲁公开课 - 文学理论导论课程节选

You just keep, you know. If you understand what's happening with the plot and you are enjoying the plot

你只要坚持看。如果你看懂了剧情，你就享受剧情好了，

要想成为读书达人 - SpeakingMax英语口语达人

They're going to understand what to do and hopefully we will understand what we need to do as well.

WSJ: Marquette-Syracuse means Big East in Final Four

But in saying that, I know we have a lot of guys that are extremely experienced, understand what it's like to play in this division, understand what it's like to play in New York because of their experience, and I like that.

WSJ: Yankees putting on Old-Timer's Day all season long

Syria would like to go back to a role that it played sporadically in the '80s and '90s, and be a country that helps Iran understand what some of the West wants, help those in the West understand what Iran wants, and gets paid handsomely by both sides for playing that role - without having to change their behaviors very much.

NPR: Defining Syria's Role in Mideast Peace