Usage note
难忘表示很容易记住，不容易忘掉。
nán wàng biǎo shì hěn róng yì jì zhù， bù róng yì wàng diào。
Unforgettable means easy to remember and hard to forget.
Context note
难忘常出现在回忆、故事和经历里。
nán wàng cháng chū xiàn zài huí yì 、 gù shì hé jīng lì lǐ。
Unforgettable often appears in memories, stories, and experiences.
5 examples
这是难忘的一天。
zhè shì nán wàng de yì tiān。
This is an unforgettable day.
他的故事很难忘。
tā de gù shì hěn nán wàng。
His story is unforgettable.
难忘的回忆。
nán wàng de huí yì。
Unforgettable memories.
这次旅行很难忘。
zhè cì lǚ xíng hěn nán wàng。
This trip is unforgettable.
老师的鼓励很难忘。
lǎo shī de gǔ lì hěn nán wàng。
The teacher's encouragement is unforgettable.
5 mini stories
那次去旅行的经历，让我觉得很难忘。
nà cì qù lǚ xíng de jīng lì， ràng wǒ jué de hěn nán wàng。
That travel experience felt very unforgettable to me.
老师对我的鼓励，我一直觉得难忘。
lǎo shī duì wǒ de gǔ lì， wǒ yì zhí jué de nán wàng。
The teacher's encouragement to me is something I always remember.
今天的活动很难忘，大家都笑得很开心。
jīn tiān de huó dòng hěn nán wàng， dà jiā dōu xiào dé hěn kāi xīn。
Today's event is unforgettable, and everyone laughed happily.
这本书里的故事很难忘。
zhè běn shū lǐ de gù shì hěn nán wàng。
The story in this book is unforgettable.
有些美好的时刻会一直很难忘。
yǒu xiē měi hǎo de shí kè huì yì zhí hěn nán wàng。
Some beautiful moments will always be unforgettable.
Mini dialogue
生日派对
A
昨天的生日派对好玩吗？
Zuótiān de shēngrì pàiduì hǎowán ma?
Was the birthday party yesterday fun?
B
非常好玩，真是一个难忘的夜晚。
Fēicháng hǎowán, zhēn shì yí ge nánwàng de yèwǎn.
It was great fun, truly an unforgettable evening.
学校旅行
A
这次学校旅行你最难忘的是什么？
Zhè cì xuéxiào lǚxíng nǐ zuì nánwàng de shì shénme?
What was the most unforgettable part of this school trip for you?
B
大家一起爬山看日出，太难忘了。
Dàjiā yìqǐ pá shān kàn rìchū, tài nánwàng le.
Climbing the mountain together to watch the sunrise was so unforgettable.
Related words and contrasts
contrast
忘记
wàng jì
to forget
难忘 means 'hard to forget', while 忘记 is the action of forgetting.
related
记得
jì de
to remember
If something is 难忘, you will always 记得 (remember) it.