1.“the other day”大家知道是什么意思，字面意思是“几天前;前两天，前几天，日前，前些日子”其实这个词的内涵意思是：不久前的某一天的一个比较模糊或不确定时间点：
He asked about you the other day.
前些日子他问到过你。
I missed the film the other day.
那天的电影，我没捞着看。
The other day I came across a friend in the street.
日前我在街上遇见了一位朋友。
以上3例来自《汉英大词典》
You came to see me at my office the other day with a business proposition
几天前你带着一份商业提案来我的办公室见我。
I phoned your office the other day
几天前我给你的办公室打过电话。
We had lunch the other day at our favorite restaurant.
前两天我们在最喜欢的餐馆吃了午饭。
My voice has got so low now I was mistaken for a man the other day on the phone.
我的声音变得很低沉，以至于前几天在电话里被人误以为是男人。
I rang her the other day and she said she'd like to come round
我前几天给她打电话，她说想过来玩。
The other day, in a little church near Brighton, a window was dedicated to the memory of the Revd. Michael Scott
几天前，在布赖顿附近的一个小教堂，人们以一扇窗户来纪念迈克尔·斯科特牧师。
I was chatting to him the other day
前几天我和他聊了一阵。
The other day we had some visitors from Switzerland
前几天我们接待了几位来自瑞士的参观者。
以上8例来自《柯林斯高阶英汉双解学习词典》
类似的表达还有：
the other night, the other morning, the other week
They had a commercial on the other night for Drug Free America that was so gross I thought Daddy was going to faint
他们前几天晚上为“美国远离毒品”组织播的那则广告非常恶心，我觉得爸爸看了都快晕过去了。
《柯林斯高阶英汉双解学习词典》
I happened to see Alice the other night.
几天前一个晚上我碰巧看见了艾丽斯。
I wrapped up my bike the other night.
我前不久的一天晚上将自行车撞坏了。
They saw us talking outside of villette's house the other morning.
他们看到你和我那天早上在依列斯特家外面谈话。
My sister came down the other week.
我姐姐几星期前到我这儿来了。
如果想要表示“另外一天”可以用“another day”来表示，它还有“又一天，再一天”的意思，例如：
Let's discuss it another day.
咱们改日再议吧！
《汉英大词典》
I think he's just going to deal with this problem another day
我想他改天就会处理这个问题。
《柯林斯高阶英汉双解学习词典》
We couldn't stay out there in that desolation another day.
在那个荒凉的地方我们一天也呆不下去了。
《汉英大词典》
Tell you what, let's stay here another day.
我想，我们可以在这里再呆一天。
《柯林斯高阶英汉双解学习词典》
With another day's work in the can, Philip is happy to leave the open countryside and head for his London flat.
又干完了一天的活，菲利普满心愉悦地离开了广袤的乡村，前往自己位于伦敦的公寓。
《柯林斯高阶英汉双解学习词典》
It was another day of mind-numbing tedium.
又是一个令人麻木的单调乏味的日子。
《柯林斯高阶英汉双解学习词典》
Another day dragged by.
又挨过了一天。
《汉英大词典》
2.one fine day
“One fine day”从字面看是“美好的一天”但是在表示一个未知的时间的时候可以引申为“突然有一天”，“总有一天”。（小编理解为过去的时间：突然间在某个不确定的或不显眼的一天（的某个未知的时间）） one fine day的英文解释：Suddenly on some unspecified or unremarkable day；at some unspecified or unknown time也就是突然间在某个不确定的或不显眼的一天（的某个未知的时间）。例如：
I hadn't seen him for ten years. Then one fine day he just turned up.我有10年没见他了，突然有一天他出现了。
Then one fine day, an existing committer of the project will send you an invitation to become a member.
有朝一日，您的能力得到了肯定，项目现有的提交者之一将发给您一封加盟邀请信。
One fine day, he just decided to step back from the relationship.
突然有一天，他决定离开这段感情。
My father decided one fine day that he wanted to buy a camper van and travel around the country.
我父亲决定，总有一天他会想要买一辆野营车然后全国到处旅游。
3.some day
表示的是“总有一天”，而不是字面上以为的“一些天”，“some day”所表示的时间是未来一个不确定的时间，是还没有发生的一天。“总有一天;有朝一日;将来”（小编理解为将来的时间：未来一个不确定的时间，是还没有发生的一天（的一个时间））
at some time in the future
Some day he'll be famous.
总有一天他会成名的。
Some day I'll be a pilot
有朝一日，我会成为一名飞行员。
I hope some day you will find the woman who will make you happy
我希望有一天你能找到一个会让你幸福的女人。
Some day I'll pay you back for this!
总有一天我会为此报复你。
以上4例来自《柯林斯高阶英汉双解学习词典》
Some day I will reciprocate your great kindness to me.
总有一天我会报答你对我的厚爱。
We shall die some day.
我们总有一天要弃世而去。
If he goes on like this, he will be imprisoned some day.
如果他继续这样下去，势必有一天要蹲监狱。
She cherishes a hope that she will be a singer some day.
她怀着总有一天要当歌唱家的希望。
以上4例来自《汉英大词典》
one day
有朝一日；（过去）某一天 at some time in the future, or on a particular day in the past
One day, I want to leave the city and move to the country.
有朝一日，我要离开城市搬到农村去。
One day, he walked out of the house with a small bag and never came back.
一天，他带了个小提包走出家门，再也没有回来。
4.great day
也不是表示“好的一天”，而是可以用在句子开口表示“我的天啊！”，我们熟悉的“我的天啊”一般是用“Oh my god!”，但是在国外其实这句话不是经常说的，而且也不能随便说。在面对虔诚的宗教徒的时候“God”可是非常神圣的，是不能够随便称呼的。
就算不是宗教信徒也不是很常说“Oh my god!”，这句话只在很惊讶的时候说，平常说大家只会觉得你戏很多，所以还是使用“great day”好一点。例句：
Great day! I didn’t expect to see you here. 我的天啊！没想到能在这里见到你。
当然，great day，也表示：一个不同寻常的日子
When the great day dawned, the first concern was the weather
当那个不同寻常的日子到来时，大家首先关注的是天气。
《柯林斯高阶英汉双解学习词典》
5.of sb's day
某人生活的时代 during a particular period of time when sb lived
the best player of his day
他那个时代最优秀的运动员
Bessie Smith was the Madonna of her day.
贝西∙史密斯是她那个时代的麦当娜。
6. in sb's day
（某人的）昔日盛时，鼎盛时期 ；年轻时；当年
She was a great dancer in her day.
她曾是红极一时的舞蹈家。
In my day, there were plenty of jobs when you left school.
我年轻时，毕业后就业机会很多。
7. make sb's day
使某人一天非常快活 to make sb feel very happy on a particular day
The phone call from Mike really made my day.
迈克打来电话，真让我一天都快乐无比。
8. black day
原来black day是指“倒霉的一天；凶日；不吉利的一天”，同理，"white day" 不是“白天”，而是“白色情人节；良辰吉日”的意思。
例句：Yesterday was a black day for me.
昨天对我来说是个倒霉的日子。
They choose a white day for their engagement.
他们选择良辰吉日订婚。
It was a black day for the aircraft workers when the government announced it wascanceling its contract for a new fighter.
当政府宣布取消生产一种战斗机的合同时，那就是航天工作者的不幸日子。
注意：
it's not sb's day
祸不单行；特别倒霉的一天
used when several unfortunate or unpleasant things happen on the same day
My car broke down and then I locked myself out─it's just not my day!
我的汽车抛锚了，我又没带房门钥匙——真是祸不单行！
9.rainy day
是指你可能会遇到困难或麻烦的一段时期。
rainy day可以指困难时期，常常搭配do something for a rainy day；save, keep, etc. sth for a rainy day也就是我们说的“未雨绸缪，以备不时之需”的意思。
看个英语例句：
I know you want to buy a new phone with your bonus，but you should really save that money for a rainy day.
我知道你想用你的奖金买一个新手机，但是你真的应该存下那笔钱以备不时之需。
最后，希望大家学习英语要贵在持之以恒，因为罗马不是一天建成的：
Rome wasn't built in a day.
罗马不是一天建成的；复杂的工作不会一蹴而就。
