“it dawns on sb that...”是一个写作或口语常用的英语表达，意思是“某人突然明白/意识到/理解/恍然大悟……” 。 “dawn”作为动词，意思是“开始明白”或“逐渐意识到，开始；变得明朗；开始清楚”；作名词是“黎明；曙光；破晓；拂晓；开端；萌芽”。这个结构通常用于描述某人突然之间对某件事情有了认识或理解。句型采用了形式主语“it”来引导出真正的主语——即后面的从句“that...”。
if sth dawns on you , you begin to realize it for the first time
请看经典例句：
1.Suddenly it dawned on me that they couldn't possibly have met before.
我突然明白他们以前不可能见过面。
2.It suddenly dawns on me that I have made a big mistake.
我突然意识到我犯了一个大错误。
3.It dawned on me that in order to move forward, I had to let go of the past and learn to embrace the present.
我恍然大悟，要继续前进，我必须放下过去，学会拥抱现在。
4. It dawned on us that we had taken the wrong bus.
我们突然意识到我们坐错车了。
16. It gradually dawned upon me that I still had talent and ought to run again.
我渐渐明白了自己还有才能，应该再次参加竞选。
5.It had just dawned on him that he had been fooled by the woman.
他刚刚意识到自己被那个女人骗了。
6.It dawned on Sarah that she had left her keys inside the house after she closed the door.
萨拉意识到她关上门后把钥匙忘在屋里了。
7.It dawns on me that I forgot to do my homework last night, and now I feel really worried about what my teacher will say.
我突然意识到我昨晚忘了做作业，现在我真的很担心老师会说什么。
8.It dawned on us that we had taken the wrong bus when we saw unfamiliar buildings outside the window.
当我们看到窗外不熟悉的建筑物时，我们恍然大悟，我们搭错车了。
9.It dawned on Lisa that she had misunderstood the instructions after she saw everyone else doing the assignment differently.
在看到别人用不同的方式做作业后，丽莎意识到她误解了指示。
10. It dawned on her that he might not come to the party.
她突然意识到他可能不会来参加派对了。
11.It suddenly dawned on me that I hadn't eaten all day.
我突然意识到自己已经一整天没吃东西了。
12. It dawns on him that he has been spending too much time playing video games instead of studying for his exams.
他渐渐明白，他花了太多时间玩电子游戏，而不是为考试而学习。
13.It didn't dawn on him until much later that she was in love with him.
他很久之后才意识到她爱上了他。
14. It dawned on him that he had forgotten his friend's birthday.
他突然意识到他忘记朋友的生日了。
15.It suddenly occurred to me that he might have forgotten our appointment completely.
我突然想到，他也许把我们的约会彻底忘记了。
16.Every time he hears this song, almost everything in his hometown will occur to him.
每当他听到这首歌曲，就会想起家乡的一草一木。
17. It dawned on me that I had left my homework at home.
我突然意识到我把作业忘在家里了。
It dawned on me that I had left the oven on. 我突然想起烤箱未曾关掉。
18. It dawned on the teacher that the students were not paying attention.
老师突然意识到学生们没有认真听讲。
19.It dawns on the team that they need to work harder if they want to win the championship this year.
这支队伍意识到，如果他们想赢得今年的冠军，他们需要更加努力地工作。
20. It dawned on me that I didn't know her phone number.
我突然意识到我不知道她的电话号码。
21. It dawned on me that I had left my wallet at home.
我突然开始意识到我把钱包落在家里了。
这个表达比较正式，适合用于书面语或正式场合的口语中。在日常口语中，人们可能会用更简单的表达，如“I realized that…”或“I suddenly understood that…”。