1.许多人看见形容词rare想当然地认为它就是一个否定意义词汇，把句子也视为否定句来处理和翻译，这是大错特错。究其原因是混淆了rare和rarely（副词）用法了。其实，rare确切含义是：为数不多的，稀有的;珍贵的;稀少的;稀罕的;半熟的;半生的，如：
There are rare instances when justice almost ceases to be an abstract conception. Reward or punishment are meted out quite independent of human interference（新概念。B3，L35）
有一些为数不多的场合，在那里正义几乎不再是一个抽象的概念。奖惩的实施是不受人的意志支配的，在这种时候，在这种时候正义就像一种活的力量在起作用。
There are rare instances when women are not equal to men.
有一些为数不多的场合，女士和男士是不平等的。
On rare occasions, crime pays well.
在为数不多的场合，犯罪是会大大获利的。（不倒装）
It's extremely rare for it to be this hot in April.
四月份就这样炎热是极其罕见的。
It must be stressed that this disease is very rare.
必须着重指出，这种病非常罕见。
The bird is now a rare sight in this country.
如今在这个国家，这种鸟已罕见了。
Some birds which were once a common sight are now becoming rare.
有些曾经随处可见的鸟类现在日益稀少。
He suffers from a rare blood disease.
他患有一种罕见的血液病。
It was a rare honour to be made a fellow of the college.
成为这所学院的研究员是极大的荣誉。
It is rare to find a prominent politician with few political enemies.
没有什么政敌的杰出从政者是罕见的。
I think it's very rare to have big families nowadays.
我想，如今大家庭已经很少见了。
On the rare occasions when they met he hardly even dared speak to her.
彼此难得相见，他还几乎不敢跟她说话。
Unhappily, such good luck is rare.
遗憾的是，这样的好运太少了。
Players as skilful as this are a rare breed.
如此有技巧的演奏者很少见。
It was a rare pleasure to see him in action.
看他打球是一种享受。
They have replanted many areas with rare and unusual plants.
他们在许多地方重新种上了珍稀植物。
Physical perfection in a human being is exceedingly rare.
体貌完美的人极为罕见。
2.rarely副词，很少;罕有;不常;很少地
rarely和hardly，little, scarcely,few,seldom,barely一样，通常具有否定的含义，含义这些副词的句子，是可以视为否定句处理的。再说的直白一点，看见这些词就当做not来处理。如：
Langdon could scarcely believe his own supposition.
兰登简直不敢相信自己的假设。
They were rarely seen together and certainly did not travel together.
很少见到他们在一起，当然更不可能一起旅行。
Journalists are rarely admitted to the region.
新闻记者很少获准进入该地区。
He is rarely satisfied with anything less than perfection itself.
他一般只对那些绝对完美的事情感到满意。
His mother had rarely criticized him or any of her children.
他母亲很少指责他或她的任何孩子。
The players are bonded by a spirit that is rarely seen in an English team.
队员们是靠一种精神拧成了一股绳，这种精神在英格兰球队中颇为鲜见。
Only rarely will she indulge in a glass of wine (放句首，倒装)
她只是偶尔才喝杯红酒，让自己享受一下。
Rarely has a debate attracted so much media attention.
难得有一场辩论吸引这么多的媒体关注。(放句首，倒装)
Rarely do schoolteachers have leeway to teach classes the way they want.
鲜有学校老师可随心所欲地教书的情况。(放句首，倒装)
Rarely, if ever, does he sidestep a question.
他极少逃避问题。(放句首，倒装)
Rarely do we see them nowadays.近来我们很少看见他们。(放句首，倒装)
At night，when you really wish to go to sleep, you rarely manage to do so.(NEC,B3,L44)
夜里当你真想入睡的时候，你却很少能成眠。
She is rarely seen in public nowadays.
如今她很少公开露面。
We rarely agree on what to do.
我们很少在要做的事情上看法一致
Over half of those questioned said they rarely took any exercise.
被问到的人有一半以上说他们很少锻炼身体。
Over half of those questioned said they rarely took any exercise.
被问到的人有一半以上说他们很少锻炼身体。
She's full of good intentions but they rarely work out.
她虽然处处出于善意，却往往事与愿违。
This disease is rarely transferred from mother to baby.
这种疾病很少由母亲传给婴儿。
I deal with customers on the phone and rarely meet them face-to-face.
我用电话和客户打交道，很少和他们见面。
We rarely agree on what to do.
我们很少在要做的事情上看法一致。
The police rarely shoot to kill.
一般来说，警察开枪不是要打死人。
The club is careful not to let the younger players be overexposed, and rarely allows them to be interviewed.
俱乐部不想让年轻队员过度曝光，因而很少允许他们接受采访。
Adolescent suicide is rarely an impulsive reaction to immediate distress.
青少年自杀很少是由于突然发生不幸而作出的冲动反应。
Dark-skinned people rarely develop skin cancer.
黑皮肤的人很少得皮肤癌。
Supplementary oxygen is rarely needed in pressurized aircraft.
密封的飞机内很少需要补充氧气。
注意：rarely,位于句首时才可能具有肯定含义：
Rarely, crime pays well.
在为数不多的场合，犯罪是会大大获利的。
3.rarely,always, never,等频率副词一般情况下应放在实义动词之前，助动词和连系动词之后，这个是个常识。但是，在省略句中，rarely等频率副词则必须放在助动词（包括情态动词）和连系动词之前。如：
San Francisco is usually cold in the summer; but Los Aageles rarely is.
旧金山夏天通常很冷；但洛斯·阿盖尔斯很少是这样。(四级真题)
Kunming is usually cool in the summer, but Shanghai rarely is.
昆明夏天通常很凉爽，但上海很少是这样。（考研真题）
A financial gain may be an ultimate goal, but it rarely is the only one.
获得利润或许是创业的最终目标，但往往并不是唯一目的。
4.hardly/scarcely/+had+主语+过去分词+when/before+过去式动词=
主语+hardly/scarcely/+had+过去分词+when/before+过去式动词
一……就
Hardly/Rarely had she arrived when/before she was asked to leave again.
She had hardly/rarely arrived when/before she was asked to leave again.
她才刚到就被只开了。
5.rarely， if ever=rarely if ever极少极少
Seldom, if ever=seldom if ever极少极少
Rarely, if ever, does he sidestep a question.
他极少逃避问题。
They could afford vacations, rarely if ever went to the movies, and didn’t have television until the mid-to late 1950s.(B. Clinton, My life)
他们没有钱去度假，看电影也是极少极少，而直到20世纪50年代的中后期才有了电视。
…his children rarely, if ever, see him at his place of work.（NEC,B4,L8）
……孩子们难得在父亲工作地点看到他。
She seldom, if ever, goes to the theatre.
她难得上剧院看场戏——即便不能说从来不去。
We see them very seldom, if ever.
我们难得见到他们。
He seldom if ever travels abroad.
他到国外旅行，即使有过，也是极少的。